“Since it is the task of the law to form and project, as well as mirror and reflect, we should not, as judges, merely recite the expectations and risks without examining the desirability of saddling them upon society.”[1]
On June 22, 2018, the U.S. Supreme Court in Carpenter v. United States held that the Fourth Amendment[2] requires the government to obtain a search warrant before acquiring from a cellular service provider seven or more days of the historic cell site location information (CSLI) generated by an individual’s cell phone.[3] In so doing, the Court held that an individual has a reasonable expectation of privacy in the whole of her physical movements.[4] Noting that CSLI creates an “intimate window into a person’s life,” the Court recognized that information’s sensitivity may serve as the basis for its protection under the Fourth Amendment,[5] even if that information is transactional data conveyed to a third party and maintained by them as a business record.[6]
Carpenter was just the latest in a string of cases in which the Court has had to grapple with rapidly changing technology’s effects on privacy.[7] But, in protecting privacy rights, Carpenter left uncertain many aspects of its application both to other quantities of CSLI and to other information created by an individual’s use of modern technologies. For example, when does the search of an aggregated data set begin and end?[8] Why does the warrantless collection of seven days of CSLI violate the Fourth Amendment, but the collection of six days’ worth might not?[9] Why does the Fourth Amendment protect historical CSLI, but such protection does not by default extend to real-time CSLI, “tower dumps” of CSLI, “conventional surveillance techniques and tools” like security cameras, or other information which might reveal a person’s location or other sensitive details?[10]
Prior to Carpenter, many labelled Fourth Amendment jurisprudence—specifically, the “reasonable expectation of privacy” test, which is the framework under which Fourth Amendment searches are gauged[11]—as inconsistent, confusing, and, most damningly, obsolete in the Information Age.[12] Certainly, the Court’s decision to declare decades-old unanimous lower-court precedent erroneous,[13] combined with these seemingly paradoxical questions flowing from the Fourth Amendment’s intersection with technological advancement, make this topic appear even more “schizophrenic” than it already had.[14] But an examination of the Court’s rationale shows the majority merely evaluated the case’s factual context by balancing the government’s burden of obtaining a warrant against the petitioner’s privacy interests, and, in doing so, it placed significant weight on whether the government’s warrantless acquisition of location data fell within the “mischief which gave [the Fourth Amendment] birth.”[15]
More interesting is what the Court’s choice to use such a balancing test in the first place reveals. Literature castigating the “reasonable expectation of privacy” test generally analyzes case law to show the test and its progeny have ruinous effects on privacy rights; these texts generally focus on the so-called Third-Party Doctrine, which lower courts created out of forty-year-old Supreme Court decisions to preclude Fourth
Amendment protection of any information voluntarily and knowingly
disclosed to a third party.[16] Insofar as these critics rebuke the Third-Party Doctrine, they would likely have an ally in the man credited as the “reasonable expectation of privacy” test’s principal architect, Associate Justice John Marshall Harlan II,[17] who first articulated it in his famous concurrence in Katz v. United States.[18] By exploring his jurisprudence and what it reveals about his views on individual privacy, this Note will demonstrate that Justice Harlan’s framework was meant to balance the government’s burden in first obtaining a warrant against the chilling effect on the reasonable person,[19] the wisdom of which was vindicated by the Carpenter majority.
Part I of this Note traces the legal protections in the criminal investigations context[20] against the government’s obtaining evidence that reveals sensitive information, from its colonial roots through today. This Part will highlight Supreme Court decisions involving then–cutting-edge technologies to illustrate the tensions between property- and possession-based approaches to the Fourth Amendment’s scope on the one hand, and a privacy-based approach on the other. Part II will analyze how contemporary advances in technology complicate and make unfeasible a broad Third-Party Doctrine.
Part III will sketch a framework of the second[21] Justice Harlan’s conception of the Fourth Amendment’s protections and how reasonable expectations of privacy should be determined. This Part will begin by analyzing Justice Harlan’s Katz concurrence, illuminated by his judicial philosophy and his opinions concerning privacy both before and after Katz. Through this evaluation, this Note will demonstrate his belief that the government must first obtain a warrant before acquiring information that would chill the reasonable person’s exercise of their intellectual and associational freedoms. It will then propose, first, that adhering to this framework would benefit individual privacy rights without unduly burdening criminal law enforcement efforts, and, second, that doing so provides the flexibility necessary to protect privacy rights as technology advances and society evolves.
Table of Contents
I. A History of the Fourth Amendment, as Applied to Evolving Technologies
A.The Fourth Amendment’s Roots and Application to Communications Through the Early Twentieth Century
B.The Fourth Amendment’s Application to Emerging Eavesdropping Technologies
C. Abandoning Property Rights as the Sole Arbiter of Fourth Amendment Protection
D. Cabining the Fourth Amendment’s Protection of Voluntarily Exposed Information
E. The Fourth Amendment’s Application to Modern Technologies
II. Problems with a Broad Third-Party Doctrine, Viewed Through a Technical Lens
A. Email
B. Web-Browsing Communications
C. Emerging Technologies: Smart Homes and Facial Recognition
III. Justice Harlan’s Jurisprudence as a Framework for Fourth Amendment Protection of Electronic Transactional Information
A. Balancing the Burdens and Benefits: Justice Harlan’s Judicial Philosophy, and the Warrant Requirement’s Scope as Determined by Chilling Effects
B. The Advantages of Justice Harlan’s Approach: Enhancing Individual Privacy Without Placing Additional Burdens on the Government
C. Objections to Justice Harlan’s Approach
1. It Will Be “Utterly Impossible to Carry on the Administration of Justice”
2. It Will “Make a Crazy Quilt of the Fourth Amendment”
Conclusion
- A History of the Fourth Amendment, as Applied to Evolving Technologies
- The Fourth Amendment’s Roots and Application to Communications Through the Early Twentieth Century
The Anglo-American tradition has embraced the maxim that “every man’s house is his castle” since the states were still colonies.[22] In fact, this principle was so engrained in the psyche of American colonists that its violation by the British helped spark the Revolution.[23] These invasions of privacy took the forms of general warrants and writs of assistance, which effectively gave British officers unfettered authority to search anywhere they pleased for evidence of criminal activity.[24] The colonies denounced these practices, calling them “the worst instrument[s] of arbitrary power, the most destructive of English liberty, and the fundamental principles of the constitution, that ever was found in an English law-book.”[25]
These unreasonable[26] and unwarranted invasions of privacy were the impetus for the Fourth Amendment’s adoption.[27] Though the Amendment’s text explicitly protects only “persons, houses, papers, and effects,”[28] it was adopted to quell the anxiety resulting from British abuses by constraining the government’s ability to invade “the sanctity of a man’s home and the privacies of life.”[29] This goal was achieved by requiring the government both to specifically define the privacy interest to be invaded and to adequately justify the invasion.[30] Even before the Amendment’s ratification and the effectuation of these limitations, the first Congress saw it fit to vest the power to issue writs, such as search warrants, in a neutral third party—i.e., the courts—so as to prevent the arbitrary and overbroad exercise of this power.[31]
The mid-nineteenth century brought about the U.S. Supreme Court’s first foray into defining the Fourth Amendment’s scope.[32] In Ex parte Jackson,[33] the Court reviewed the constitutionality of a federal statute which prohibited sending certain types of mail through the postal service.[34] The Court ultimately held the statute to be a constitutional exercise of congressional power,[35] but explained that its enforcement must comport with the Fourth Amendment’s proscriptions.[36] This clarification of the Amendment’s protective scope distinguished between what an individual intends to keep secret, such as the contents of sealed letters and packages, and what is left open to examination by virtue of its form, such as a newspaper or pamphlet.[37] This determination—that a sealed letter or package is protected by the Fourth Amendment, except for what is discernable without unsealing it—distinguished communicative content from transactional information revealed to a service provider in the ordinary course of business.[38] The Court, in so doing, relied on the inherent nature of an individual’s “papers” to potentially contain highly sensitive information, regardless of whether or not he possesses them.[39]
The decades following Jackson saw new technologies like the camera and the telephone arrive, and, with them, new ways of intruding on privacy.[40] Yet, the Supreme Court during these years refused to impose restrictions on the government’s exploitation of these technologies.[41]
For example, the Court in Olmstead v. United States[42] considered whether the warrantless wiretapping of a telephone from a public street violated the Fourth Amendment.[43] Chief Justice Taft’s majority opinion held that the Fourth Amendment’s protections did not extend to Olmstead’s phone conversation for two reasons: first, there was no physical intrusion by the government onto his property; and second, a phone conversation is not tangible and thus could neither be searched nor seized, unlike papers and effects.[44] The Court’s rejection of the private phone conversations as analogous to the sealed letters in Jackson underscored the formalist and property-based reasoning employed by the majority.[45]
In dissent, Justice Brandeis emphatically condemned the majority’s property-based rationale.[46] Justice Brandeis highlighted that the government had available to it more surreptitious and effective means of invading privacy than could have been imagined when the Bill of Rights was adopted;[47] therefore, limiting the Fourth Amendment’s application to only those categories explicitly enumerated would betray its core principle of “protect[ing] Americans in their beliefs, their thoughts, their emotions and their sensations.”[48] In direct opposition to the majority’s rejection of the sealed-letter analogy, Justice Brandeis asserted the equivalence of wiretapping to unlawfully opening an individual’s mail.[49] He contended that, like with letters and packages, the Fourth Amendment should protect from interception the contents of an individual’s phone conversations due to the scope and sensitive nature of what they might reveal.[50]
For the better part of the next four decades, Olmstead’s property-based standard governing the Fourth Amendment’s application to emerging technologies not only remained in place but was significantly expanded.[51] In 1942, the Supreme Court in Goldman v. United States[52] ruled that the government’s pressing a device against a wall to listen to conversations in the adjoining room did not violate the Fourth Amendment because the device did not invade the participants’ property rights.[53] In 1952, the Court in On Lee v. United States[54] declined to invalidate the government’s eavesdropping on a conversation between the defendant and an acquaintance wearing a wire.[55] The Court, which relied on the absence of an invasion of On Lee’s property rights by the government itself,[56] determined that the use of a wire under the circumstances was, at best, an “attenuated analogy to wiretapping.”[57]
Nine years later, the Court in Silverman v. United States[58] was given the opportunity to re-examine its prior decisions in light of the admittedly “frightening paraphernalia” of evolving electronic surveillance capabilities, but it declined to do so and instead grounded its unanimous opinion in property law.[59] In that case, the government inserted a microphone through a wall until it made physical contact with a heating duct, which allowed agents to eavesdrop on the neighboring home through the duct’s reverberations.[60] The Court held the government ran afoul of the Fourth Amendment because it physically encroached into a “constitutionally protected area.”[61]
Not until thirty-five years after Olmstead did the Court for the first time rest a Fourth Amendment decision on a foundation of privacy instead of property, at least in part.[62] In 1963, the Court in Lopez v. United States[63] analyzed whether a federal revenue agent violated the Fourth Amendment by secretly recording Lopez offering him a bribe to not perform a tax audit.[64] Justice Harlan, writing for the majority, highlighted that the government, through its agent, was a party to the conversation and thus was privy to its content. Therefore, the agent did not violate the Fourth Amendment since the content was not surreptitiously and deceitfully obtained by the government, but rather knowingly and voluntarily conveyed to the government by Lopez.[65]
Many of the cases heard by the Supreme Court in the 1960s drastically changed Fourth Amendment jurisprudence.[66] For example, in May 1967, the Court in Warden, Maryland Penitentiary v. Hayden[67] vindicated the notion that privacy, not property, is the “principal object” of the Fourth Amendment.[68]
Exactly two weeks later, the Court further chipped away at the long-standing and controversial[69] Olmstead decision in Berger v. New York.[70] In Berger, the Court struck down a New York law which authorized eavesdropping because the statute lacked adequate procedural safeguards.[71] The Court analogized orders issued under the statute’s
authority to general warrants and held they effected unconstitutional invasions of privacy.[72] This decision primarily relied on property-based reasoning that the contested statute permitted unfettered intrusion into a “constitutionally protected area.”[73] But Berger’s conclusion that the government violated the Fourth Amendment by relying on the facially unconstitutional statute partially weighed the sensitivity of what eavesdropping could reveal.[74]
Just over six months later, the seminal Katz v. United States[75] sounded the official death knell for Olmstead’s proposition that the Fourth Amendment does not protect against surveillance absent either a physical trespass or the seizure of a material object.[76] In that case, the government placed listening devices on the outside of an enclosed public telephone booth it knew Katz frequently used to place illegal interstate bets.[77] Although both parties tailored their briefs to the property-based questions certified by the Court,[78] the majority ultimately rejected this framing of the legal issues.[79] Instead, the Court relied on Katz’s expectation of privacy in his private phone conversations to hold that the government’s eavesdropping violated the Fourth Amendment.[80] In doing so, the Court declared:
[T]he Fourth Amendment protects people, not places. What a person knowingly exposes to the public, even in his own home or office, is not a subject of Fourth Amendment protection. But what he seeks to preserve as private, even in an area accessible to the public, may be constitutionally protected.[81]
Thus, the Court overruled Olmstead to the extent the Fourth Amendment’s protections solely turned on an encroachment of a property interest.[82]
Notably, the Court acknowledged that the government complied with the Fourth Amendment’s requirements, save for one crucial step: obtaining a warrant.[83] Warrantless searches, said the Court, are “per se unreasonable” and are valid only if at least one of a limited number of narrow, context-specific exceptions was satisfied, none of which applied in Katz.[84]
In his oft-quoted concurring opinion,[85] Justice Harlan agreed with the Katz majority that “the Fourth Amendment protects people, not places.”[86] Justice Harlan then set out to articulate a framework, based on what he understood the confluence of the Court’s prior decisions to protect, for determining the applicability of the Fourth Amendment’s warrant requirement.[87] He wrote: “[T]here is a twofold requirement, first that a person have exhibited an actual (subjective) expectation of privacy and, second, that the expectation be one that society is prepared to recognize as ‘reasonable.’”[88] This framework, now colloquially known as the “reasonable expectation of privacy” test, incorporated into the scope of the Fourth Amendment’s protections the contents of electronic communications based on the context in which they are acquired, without disturbing the protections inherent in property rights.[89] Justice Harlan, analyzing the facts of the case, first reasoned that Katz had shown a subjective expectation of privacy by shutting the door of the phone booth and paying the toll to use the phone, temporarily making the booth a private place.[90] He further explained that the Court’s prior holdings protecting the contents of a phone conversation made this expectation of privacy objectively reasonable.[91]
To the extent Katz seemed to ground the Fourth Amendment in protecting all sensitive information, that notion was refuted not long after. From the time Katz was decided through the turn of the new millennium, the Court continued to use Justice Harlan’s test[92] but injected property-based reasoning that restricted individual privacy rights by limiting what people could subjectively or objectively have reasonable expectations of privacy in.
In United States v. White,[93] for example, federal agents obtained inculpatory evidence by listening to White’s conversations with a government informant who was wearing a wire.[94] White and the informant had four of the eight monitored conversations in the
informant’s home, where each was concurrently overheard by one agent hiding in a kitchen closet[95] and another outside listening with a radio receiver.[96] The other conversations were overheard solely through the informant’s wire.[97] A plurality of the Justices, which did not include Justice Harlan, declined to differentiate between an informant without a wire, who could write down and testify to the content of a conversation without running afoul of the Fourth Amendment, and an informant wearing a wire, whose recording or transmitting the conversation merely produces a “more reliable rendition” than the informant’s memory would.[98] This rationale drew on prior cases to support the proposition that the Fourth Amendment does not protect the misplaced belief that someone to whom information is voluntarily disclosed will not later reveal that information to the government.[99] The plurality also noted that Katz, which did not involve a third-party disclosure, did not address whether a speaker could have a “justifiable and constitutionally protected expectation” that the listener would not later reveal that conversation’s content to the government.[100]
Eight years after White, the Court considered whether an individual has a reasonable expectation of privacy in the numbers they dial on a telephone.[101] In Smith v. Maryland, a foundational case for the Third-Party Doctrine,[102] the Court answered this question in the negative.[103] The
Court first explained that telephone service subscribers cannot have any subjective expectation of secrecy in the numbers they dial because they knowingly and voluntarily give the numbers to the phone company, which the subscriber knows can, and indeed does, record the dialed numbers for “a variety of legitimate business purposes.”[104] Accordingly, Smith could not have exhibited a subjective expectation of privacy in the numbers he dialed, even though he used the telephone in his home “to the exclusion of all others.”[105] Rather, he could only expect to keep the contents of his conversations private.[106]
The Court further noted that even if Smith had demonstrated a subjective expectation that the dialed numbers would remain confidential, such an expectation was not objectively reasonable.[107] The Court, relying on similar cases as in White, reasoned that Smith voluntarily disclosed the numbers he dialed to the phone company in the ordinary course of business and therefore “assumed the risk” that the phone company would later divulge this information to the police.[108] This rationale, which did not consider the sensitivity of the information but rather relied on the nature of its creation and of its subsequent use,[109] further entrenched into constitutional protections the “line between what a person keeps to himself and what he shares with others.”[110]
The decades following Smith brought before the Supreme Court cases involving the rapidly advancing technologies of the late twentieth and early twenty-first centuries. For example, the Court in the early to mid-1980s, in United States v. Knotts[111] and United States v. Karo,[112] considered the Fourth Amendment’s application to the government’s use of radio transmitters[113] to track criminal suspects on public roads[114] and in their homes,[115] respectively. The Court’s answer to these questions—that a reasonable expectation of privacy does not exist as to tracking on public roads[116] but does exist as to tracking in the home[117]—relied on the private nature of the surveillance subject’s location and, like in Smith, on whether the information obtained through that surveillance was knowingly exposed to third parties.[118] That is, the Fourth Amendment did not protect against tracking on public roads because “[t]he information obtained . . . was ‘voluntarily conveyed to anyone who wanted to look,’” whereas the opposite was true for tracking in the home.[119]
Kyllo v. United States[120] provides another example. Just after the turn of the twenty-first century, the Court considered the Fourth Amendment’s application to thermal imaging technology that allowed the government to see activity inside a home from outside of it.[121] Justice Scalia’s majority opinion held that using this technology, which was not in general public use, was a search because it provided law enforcement a way to see what was otherwise imperceptible absent a physical intrusion into the home.[122] The Court found a reasonable expectation of privacy against any government intrusion into the home, which flowed directly from the Fourth Amendment’s text and its common-law roots.[123] The Court explicitly rejected the government’s argument that a search occurs only if the surveillance at issue reveals “intimate details.”[124] In so doing, the Court not only reasoned that this standard’s subjectivity would create too much ex ante uncertainty,[125] but also that “all details are intimate details” when they relate to the “sanctity of the home.”[126] The Court in Kyllo, like in Knotts and Karo before it, indicated that it was further developing the “reasonable expectation of privacy” test articulated in Justice Harlan’s Katz concurrence.[127] However, all three cases dismissed the importance of the sensitivity of what would potentially be revealed by the government’s conduct and instead relied on the special solicitude of the home.
Following the advent of the Internet, the Court largely shied away from cases involving modern technology’s implications on the Fourth Amendment.[128] For example, the Court in 2010 for the first time addressed the Fourth Amendment’s application to then-largely obsolete pager technology.[129] However, the issue was in the context of a government employee’s Fourth Amendment rights in the employment
context, where “‘special needs, beyond the normal need for law enforcement,’ make the warrant and probable-cause requirement impracticable for government employers.”[130] And, even then, the Court explicitly warned the judiciary against weighing in too soon on new technology.[131]
Eleven years after Kyllo, the Court in United States v. Jones[132] considered a question analogous to that in Knotts: whether the government’s use of real-time tracking technology to monitor a vehicle’s movements on public roads over a four-week period was a search under the Fourth Amendment.[133] In Knotts, the government, with the owner’s consent, had installed in a chemical drum[134] a beeper that would assist in tracking the defendant’s car by transmitting radio waves that could be lost once out of the receiver’s range;[135] the drum was later sold to the defendant, who was not informed of the beeper.[136] The Court concluded that a person traveling on public roads had no reasonable expectation of privacy in their movements between places.[137]
In Jones, however, the government physically attached a Global Positioning System (GPS) tracking device, which was more accurate and comprehensive than the beeper in Knotts[138] and which was not subject to
the same physical limitations,[139] to the defendant’s wife’s car without her knowledge or consent.[140] The Court, in contrast to Knotts, unanimously held the government violated the Fourth Amendment.[141] However, the Justices split on the underlying rationale.
Justice Scalia’s five-Justice majority opinion was rooted in common-law property and tort concepts. This opinion reasoned that because the car was the defendant’s “effect” within the meaning of the Fourth Amendment’s text, attaching the GPS device to its exterior was a physical intrusion and thus was a search requiring a warrant.[142] In so holding, the majority explicitly refused to apply the “reasonable expectation of privacy” test because the case could be resolved through a simpler analysis.[143] Nevertheless, the majority acknowledged that situations involving no trespass, such as electronic surveillance, would be subject to the Katz standard.[144]
Justice Alito, although he concurred in the judgment, rebuked the majority’s property-based rationale as “artificial” and inapposite in light of cases decided since Katz.[145] Joined by the remaining Justices, he argued that the government’s use of a GPS device for long-term tracking was the critical factor, not the seemingly minor physical trespass of attaching the device to the car’s exterior.[146] Citing the increasing pervasiveness of network-based technologies, Justice Alito endorsed Justice Harlan’s Katz concurrence as the superior analytical framework to avoid issues that would inevitably arise from the majority’s trespass-based approach in a world where one frequently is not required to conduct invasive surveillance.[147]
Justice Alito also recognized the sensitive nature of what could be revealed by such unrestricted surveillance. He argued that an expectation
of privacy’s reasonableness should be gauged by how the average person’s expectations about her privacy are shaped by technological advancements.[148] Justice Alito reasoned that while a person may anticipate that she would be watched for a short time, the surveillance here invaded a reasonable expectation of privacy because its length would consume vast resources that the government might otherwise question expending in the absence of the tracking technology.[149] This approach, which suggests that police actions in the aggregate may constitute a Fourth Amendment search even where the isolated actions do not, has become known as the “Mosaic Theory” of the Fourth Amendment.[150]
Justice Sotomayor’s solo concurrence cut a middle path between the other two opinions. Although she provided the crucial fifth vote to the majority’s property-based approach to the instant case’s facts,[151] Justice Sotomayor wrote separately to express her concern that such an approach was too narrow in the grand scheme of Fourth Amendment jurisprudence.[152] Troubled by the prospect that even short-term monitoring could chill the exercise of constitutionally protected speech and association, she also supported Justice Alito’s contention that determining a privacy expectation’s reasonableness—and thus whether the warrantless invasion of that expectation runs afoul of the Fourth Amendment—requires an examination of the expectation in context.[153] However, unlike Justice Alito’s version of the Mosaic Theory, which focused on whether society would see the government’s investigative method as reasonable,[154] Justice Sotomayor argued that this analysis must consider the chilling effect that validating the privacy invasion would have on the reasonable person.[155]
Just two years after Jones, the Court in Riley v. California[156] addressed whether the “search incident to arrest” exception[157] to the Fourth Amendment’s warrant requirement applied to the contents of an arrestee’s cell phone.[158] Notwithstanding the diminution of what an individual could reasonably expect to remain private due merely to the fact of their arrest,[159] all nine Justices voted against extending the exception to the contents of cell phones.[160] Instead, the Court held that the government must obtain a warrant to search this information.[161] In so doing, the Court, moving away from property-based reasoning, compared the ubiquity of cell phones in modern society,[162] the massive volume of data typically accessible from them,[163] and the sensitivity of such data[164] with other objects that might be found on an individual’s person.[165]
The latest chapter in the Fourth Amendment’s application to modern technologies and the sensitive information they can reveal is Carpenter v. United States.[166] In Carpenter, federal agents arrested four men suspected of robbing a series of stores, who in turn furnished several of their accomplices’ cell phone numbers.[167] The government applied for
court orders, pursuant to the Stored Communications Act (SCA), directing the numbers’ respective wireless carriers to furnish the associated business records, including the CSLI.[168] An order issued under the SCA—as opposed to a warrant, which requires a showing of probable cause[169]—permits the government to access certain electronically stored information upon a showing of “specific and articulable facts” that the information sought is reasonably “relevant and material to an ongoing criminal investigation.”[170] Accordingly, the question presented in Carpenter rested at the intersection of the Third-Party Doctrine and the location-tracking cases: whether the government violated the Fourth Amendment by obtaining CSLI from a cellular service provider without a warrant.[171]
Contrary to all federal circuit courts of appeals to address the CSLI question,[172] the Court held that an individual’s disclosure of transactional information to a third party for “legitimate business purposes”—in this case, the cellular service provider—did not by itself preclude Fourth Amendment protection of that information.[173] The majority instead ruled that an individual has a reasonable expectation of privacy in her historical CSLI,[174] and the government must generally obtain a warrant supported by probable cause to acquire it without running afoul of the Fourth Amendment.[175] The Court distinguished CSLI from the transactional information in Smith based on several factors: the pervasiveness of the technology that created the information,[176] the creation of such data merely by participating in a necessary part of modern society and oftentimes without any affirmative action by the user,[177] the retrospective and comprehensive scope of the information,[178] and the sensitivity of what the information may reveal.[179] Despite this rationale, however, some lower courts have hesitated to extend Carpenter to other technologies that may reveal sensitive information, or even other categories or quantities of CSLI, in light of the case’s explicitly narrow holding.[180]
Despite the contention of three of the four dissenting Justices, Carpenter was not a rejection of prior precedent.[181] The majority did not disregard the Third-Party Doctrine, but rather declined to extend forty-year-old decisions to endorse a wholesale doctrine created by the lower courts that it had never approved in the first place. That is, the Court did not reverse or abandon its prior decisions, but merely corrected lower courts’ decisions that erroneously interpreted cases like Smith.[182]
When the Court decided Smith, what transactional information necessarily conveyed to a third-party service provider revealed, while sensitive, could arguably be considered minimally intrusive into a person’s private life. For example, pen registers and trap-and-trace devices, respectively, capture the addressing information of outgoing or incoming signals, such as phone numbers, but not the substantive information transmitted by those signals, i.e., the content of the communication.[183] Due to these revelations, the phone company—and through it, the government—knew with whom an individual associated, but not the nature of those associations.
Modern analogs, however, may reveal more about an individual than most could have imagined only four decades ago.[184] The GPS location data discussed in the Jones concurrences[185] and the CSLI at issue in Carpenter[186] are just two examples of technologies to which applying the Third-Party Doctrine would betray the principle at the Fourth Amendment’s core: to protect an individual’s “familial, political, professional, religious, and sexual associations”[187]—namely, the “privacies of life.”[188] This Part will discuss discrete examples of some of the most commonplace and on-the-rise technologies, including how they function, to illustrate how the Third-Party Doctrine, if left to stand for the wholesale exclusion of all information conveyed to a third party, would render the Fourth Amendment impotent in a world where sensitive information is necessarily transmitted to third parties through the everyday participation in society.[189]
Email, perhaps, is the best technology with which to begin this Part’s discussion, both because of its widespread use[190] and because of its similarities to traditional mail. An email consists of two sections: the body and the header.[191] Information in the header generally resembles the information on the outside of a traditional envelope in that it shows the information related to addressing, i.e., the sender and the recipient.[192] But, in contrast, an email header also shows a plethora of other information, such as the Internet Protocol (IP) addresses of the specific servers[193] the email passed through along the way to its destination and at what date and time it did so.[194]
Courts have generally afforded the same Fourth Amendment protections to the body of an email as they do the contents of sealed letters and phone calls.[195] The reasoning for this is generally threefold. First, Internet Service Providers (ISPs), which facilitate the global transfer of data,[196] and email service providers are necessary intermediaries for the communication to be made. Thus, they are the functional equivalents of the phone company and postal service, and the content of an email is equivalent to the content of a phone call or letter.[197]
The second and third lines of reasoning, respectively, are the flip-sides as to why an email header receives as little protection as the transactional information of sealed letters and phone calls under Jackson and Smith, respectively.[198] Like the postal service and phone companies, ISPs and email providers are the intended recipients of the part of the message containing transactional information, which in itself is a message to them conveying instructions about how to handle the email.[199] However, the service providers are not the intended recipients of the body of the email, or the “main” communication, which, like an individual’s papers, potentially contains sensitive and confidential information sent by one user to another.[200] In short, lower courts have generally construed the Fourth Amendment to not protect email headers because, like the addressing information on traditional envelopes and phone numbers dialed, this information seemingly lacks sensitivity and is voluntarily and necessarily divulged to the service provider so the message can be delivered.
Though the email’s body and header clearly contain content and information related to addressing, respectively, the header also contains a piece of information that is not analogous to any part of a traditional letter: the subject line.[201] Because the subject line is located in the header, it could arguably be classified as transactional information. It is easy, therefore, to see how a reading of Smith that precludes constitutional protection of all transactional information knowingly and voluntarily conveyed to a third party could leave this piece of information unprotected by the Fourth Amendment.[202] Notably, however, there is a general consensus that the subject line is content and that a warrant should be obtained before acquiring it. This is because it tends to communicate “information concerning the substance, purport, or meaning” of the email, in line with the SCA’s definition of “content.”[203] And, by passing the SCA with this definition, Congress authoritatively signaled that our society is “prepared to recognize as ‘reasonable’”[204] an expectation that an email’s subject line be subject to the same protections as its body.
Though almost all Americans who use the Internet do so for email,[205] they also conduct myriad other activities.[206] Many of these activities occur over the World Wide Web (the Web).[207] Though the Web’s user experience is simple enough and familiar to most,[208] the technology relies on many moving parts. And, because there are so many parts, a broad application of the Third-Party Doctrine would allow the government to
have easy access to information which could be used to paint a more revealing picture of the “privacies of [a person’s] life”[209] than CSLI can.
Understanding how these various components work in tandem is critical to comprehending why applying the Third-Party Doctrine to the Web can be so problematic for privacy. When a user browses the Web, she generally interacts with a web page, or a document that can be displayed in a web browser.[210] A web page’s exact location is identified by a Uniform Resource Locator (URL).[211] Websites are made of multiple inter-connected web pages and are hosted, or “live,” on a web server.[212] Because web servers are themselves computers, they have IP addresses that are used by other computers to identify them.[213] But web servers can also be identified by a word-based domain name, which is easier for humans to remember than a series of numbers.[214]
Which IP address corresponds to each domain name is stored on Domain Name System (DNS) servers, much like a person’s phone number or physical address is stored in a traditional phone book.[215] When a user directs their web browser to a new web page, the browser sends a message containing the domain name to a DNS server—which is oftentimes operated by the ISP[216]—requesting the corresponding IP address, which is subsequently returned to the browser.[217] The browser then sends to those web servers, through the ISP, a message containing a request for a copy of the specific web page identified in the URL.[218] Like all Internet traffic, this message is sent as a packet divided into addressing information—i.e., the web server’s IP address, which is given to the ISP to direct the packet—and content—i.e., the request to the website operator for the specific web page.[219] It is common practice for both ISPs and website operators to keep records of user activity, including the user’s IP address and the specific pages they view.[220]
Additionally, small text files called “cookies,” which store data about a user and their activity on the hosted website, such as their name, address, and items in their shopping cart, are sometimes placed by web servers onto computers that visit them.[221] Though cookies can only be read by the server that left them on the computer, many website operators rent advertising space to companies, which in turn also enables the renter
to leave a cookie.[222] Many online advertising companies, such as Google,[223] rent space on thousands of websites, thus enabling them not only to leave cookies on the computers of visitors to all those websites,[224] but also to retrieve their cookies from all of those visitors.[225] Cookies serve many useful functions, such as preventing a user from having to log in each time they visit a password-protected webpage.[226] But they also allow companies like Google to track a user’s activity across the Web so they can target advertisements to that user’s preferences, including content, services, and other products.[227]
In sum, an ISP knows which IP addresses a user communicated with; a DNS provider—or an ISP, if it operates the DNS server—knows the domains for which a user looked up the IP address; a web server knows which individual webpages a user viewed, and potentially how that user interacted with those webpages; and an online marketing platform such as Google, if it can associate a cookie with a user, can track the webpages a user viewed without the help of the other three components. And, under an expansive version of the Third-Party Doctrine, none of this information would be protected by the Fourth Amendment’s warrant requirement.
Individually—and especially together—this information can be used to paint a revealing picture about a user, even over a short time.[228] This is true whether the information is captured by the government’s use of a pen register to intercept the information[229] or whether it is turned over to the government from the records of an ISP, a DNS provider, a server, or an advertiser.[230] IP addresses, and oftentimes cookies,[231] are similar to transactional information such as the numbers dialed from a telephone insofar as they are necessarily conveyed to a third party while using Internet-based services, and they may divulge the existence of various associations by revealing with whom or what an individual has communicated.[232] However, in contrast to phone numbers dialed, and like CSLI, transactional information about Web-browsing activity is created merely by interacting with modern society in an almost-necessary way,[233] and they can surely form a comprehensive and retrospective record of an individual’s Web-based activity.[234] This same information can also more readily reveal about an individual the nature of “their beliefs, their thoughts, their emotions,”[235] and their associations than even CSLI can.
For example, a user’s Web-browsing activity could generate the following logs at her ISP:
[2015/03/09 18:34:44] abortionfacts.com
[2015/03/09 18:35:23] plannedparenthood.org
[2015/03/09 18:42:29] dcabortionfund.org
[2015/03/09 19:02:12] maps.google.com[236]
An individual’s time-stamped Web-browsing records, like GPS information and CSLI, may reveal an individual’s movements, or at least allow them to be inferred, as in the above example. But they certainly do provide an “intimate window” into an individual’s life by revealing her various—and potentially sensitive—associations.[237]
As the efficiency and speed with which data is processed and transmitted have increased,[238] technologies which capitalize on those advances have developed in tandem.[239] These technologies do not always fall within the scope of electronic communications, but they implicate many of the same concerns regarding the Fourth Amendment.
One such example is “smart home” technology. This technology, built on top of the Internet of Things,[240] enables a user to remotely control tasks around her home, and it often includes artificial intelligence that self-adapts based on usage patterns.[241] The convenience of starting the coffee machine and shower before leaving the comfort of bed each morning certainly is appealing, but the tradeoff is the required disclosure of sensitive information—what one does around their home—to third parties.[242] As voice-controlled home assistants like Amazon Echo or Google Home gain popularity,[243] even more of this information will be conveyed to those third parties,[244] thus providing them—and through them, the government[245]—more of an “intimate window into a person’s life,”[246] thus rendering the “privacies of life”[247] no longer private.[248]
Another groundbreaking technology is facial recognition software. In mid-2018, it was reported that Amazon had developed such a program, and that it could operate in real-time and track a person or object through multiple cameras.[249] Moreover, Amazon had licensed its use to various government entities[250] and had approached others about doing the same, including U.S. Immigration and Customs Enforcement.[251] This software can undoubtedly be beneficial in some contexts.[252] But, when combined with the prevalence of video cameras capturing public areas,[253] it raises issues analogous to those in Carpenter, not the least of which is the ability of law enforcement to effortlessly, comprehensively, and retrospectively monitor an individual’s public movements and potentially sensitive associations.[254]
Neither Congress[255] nor the courts have yet spoken on the permissibility of the government’s use of facial recognition technology;[256] only time will tell if and how the Fourth Amendment restricts its use.[257]
III. Justice Harlan’s Jurisprudence as a Framework for Fourth Amendment Protection of Electronic Transactional Information
The lower court decisions creating wholesale doctrine out of Smith have led numerous scholars to argue that Justice Harlan’s “reasonable expectation of privacy” test has allowed the government to undermine the Fourth Amendment’s protections against arbitrary intrusions into citizens’ lives.[258] Some of these scholars have further discussed how to adapt this standard to protect privacy rights as technology evolves.[259] However, Justice Harlan’s judicial philosophy and opinions concerning privacy provide a context for understanding the Katz test that is more solicitous of individual privacy, especially in light of advancing technology, than many of these scholars give it credit for.
- Balancing the Burdens and Benefits: Justice Harlan’s Judicial Philosophy, and the Warrant Requirement’s Scope as Determined by Chilling Effects
Chief among the key characteristics of Justice Harlan’s judicial philosophy was his profound belief in two principles that go hand-in-hand: judicial self-restraint[260] and adherence to precedent, or stare decisis.[261] Justice Harlan was known to abide by these even when he personally disagreed with the policy or practice at issue or with the relevant precedent.[262] The deference Justice Harlan’s Katz concurrence accorded “the rule that ha[d] emerged from prior decisions” illustrates his practice of incrementalism.[263]
Careful legal analysis and deliberate word choice were also central to Justice Harlan’s opinions.[264] The particular words he chose for his Katz concurrence—that Fourth Amendment protections “[g]enerally, as here, . . . require[] reference to a ‘place’”[265]—show Justice Harlan acknowledged that determining the warrant requirement’s applicability calls for a context-based evaluation in all situations, not just in those involving electronic communications, and that such an analysis necessarily requires a “reference” point.[266] This “answer” to the question
of “what protection [the Fourth Amendment] affords to those people” it protects highlighted that conceptions of privacy are shaped by attendant circumstances.[267] This observation is representative of a broader principle: a privacy expectation’s reasonableness is gauged by measuring behavior against societal norms external to the notion of privacy itself.[268] Justice Harlan highlighted that the context generally—but not always[269]—dictates that reasonableness turns on the nature of the relationship between the activity and the characteristics of the place where it occurred.[270]
In true character, Justice Harlan did not venture in Katz to articulate which norms to measure reasonableness against when the event’s location does not provide the necessary context. That answer, however, is provided by other aspects of Justice Harlan’s jurisprudence, particularly his views on substantive due process.
Justice Harlan famously rejected the incorporation of the Bill of Rights to the states via the Fourteenth Amendment’s Due Process Clause,[271] in part because he believed it unduly “restrict[s] the reach” of due process.[272] He instead championed the idea that due process, as embodied in the Fifth and Fourteenth Amendments,[273] represents the
broader balance between the rights of the individual and the needs of society.[274] That is, he believed due process guarantees those rights fundamentally “belong[ing] . . . to the citizens of all free governments,”[275] as informed by the history of the relevant constitutional provision and the legal traditions that grow out of it[276]—those rights that are “implicit in the concept of ordered liberty.”[277] Justice Harlan accordingly believed an expectation of privacy “that society is prepared to recognize as ‘reasonable’”[278] is one that could be “rationally perceived”[279] as growing out of the traditions at the core of the Fourth Amendment. When combined with his explicit endorsement of Justice Brandeis’s exposition of the Fourth Amendment’s origins and purposes in Olmstead,[280] it becomes clear that Justice Harlan believed the Fourth Amendment protects “the sanctity of a man’s home and the privacies of life,”[281] to wit,
it protects “Americans in their beliefs, their thoughts, their emotions and their sensations.”[282]
In short, Justice Harlan believed that an expectation of privacy’s reasonableness—and thus whether a warrant must first be obtained before intruding on that expectation[283]—turns on whether the factual context of the case is such that the government conduct at issue, if unconstrained, would “undermine that confidence and sense of security in dealing with one another that is characteristic of individual relationships between citizens in a free society.”[284]
The chilling effects caused by modern government surveillance, including that of metadata and transactional information as well as communicative content, are well-documented in case law and scholarship alike.[285] Justice Harlan, therefore, likely would have believed that an individual has a reasonable expectation of privacy in much of the transactional information created by modern technology’s use. However, he also recognized that such an expectation’s reasonableness might diminish in certain situations. These include circumstances where the chilling effect is not as great,[286] such as when the information is voluntarily conveyed to the government itself,[287] or where the government’s burden would be too great, such as in exigent circumstances.[288] His ultimate point was that “[s]ince it is the task of the
law to form and project, as well as mirror and reflect, we should not . . . merely recite the expectations and risks without examining the desirability of saddling them upon society.”[289]
In this respect, Justice Harlan’s vision of when a warrant is required resembles Judge Learned Hand’s famous balancing test in United States v. Carroll Towing.[290] In that case, Judge Hand attempted to quantify the theory of negligence by proposing that a party is liable when its burden of taking precautions against harm to others is outweighed by the product of the probability of that harm occurring and the realized gravity of that harm.[291] More simply, Carroll Towing stands for the proposition that a party has breached an obligation they owe society when the costs borne by society outweigh the costs the party would have incurred had they taken preventative measures.
Comparably, Justice Harlan believed the government’s duty of care—its obligation to ensure searches are not unreasonable—is breached when the potential chilling effect on the reasonable person outweighs the government’s burden to obtain a warrant.[292] Under this approach, the government satisfies its duty of care, and thus complies with the Fourth Amendment, where it obtains a valid warrant before acquiring sensitive information. That is, the valid warrant mitigates the “damages,” i.e., the suppression of evidence.[293] But, where the government does not obtain a warrant, a court must determine whether to define the government’s intrusion as a category of searches that, viewed systemically, would have such a large chilling effect that it is worth imposing the aggregate burden on the government to get a warrant for all such acquisitions. The wisdom of this approach was vindicated by the Carpenter majority, which recognized that, to obtain sensitive information absent a special weight applied to one side of the scale,[294] “the Government’s obligation is a familiar one—get a warrant.”[295]
- The Advantages of Justice Harlan’s Approach: Enhancing Individual Privacy Without Placing Additional Burdens on the Government
As Justice Harlan wrote, “Authority is hardly required to support the proposition that words would be measured a good deal more carefully and communication inhibited if one suspected his conversations were being transmitted and transcribed.”[296] Just as intuitive are the benefits of applying the above balancing test to electronic transactional information, which would account for its contextual sensitivity instead of applying bright-line rules such as the Third-Party Doctrine.
It is obvious that privacy rights would benefit from constraining the government’s ability to access information based on its sensitivity rather than on whether it neatly fits a label such as “content.”[297] Also apparent is what those benefits are. Individuals would have the necessary breathing room to experiment with new ideas and ideologies,[298] leading to a polity with increased critical thinking skills. This, in turn, increases democratic self-governance and innovation.[299] In contrast, an increase in surveillance leads to the opposite: a docile, conditioned society in which civic engagement and cultural and technological progress stagnate.[300]
With respect to the effect such a test would have on the government’s investigative efforts, it is important to remember that the Katz test determines only whether the government conduct is a Fourth Amendment search and thus requires a warrant. Determining that an expectation of privacy in electronic transactional information is reasonable does not completely foreclose law enforcement from engaging in the conduct at issue. Rather, it merely prevents such conduct unless a “detached judicial officer” has determined probable cause exists to suspect the subject’s involvement in unlawful activity.[301] Accordingly, the balancing test places no more of an onus on the government than it currently has in situations involving an invasion of privacy in the physical realm: “get a warrant.”[302]
- Objections to Justice Harlan’s Approach
- It Will Be “Utterly Impossible to Carry on the Administration of Justice”[303]
The above discussion of the advantages of Justice Harlan’s approach (purposely) glosses over a serious problem. As was highlighted in Carpenter by both the government and Justice Alito, the government must start an investigation somewhere. And, if every investigative technique requires a warrant, “[m]any investigations will sputter out at the start.”[304] This will only become more problematic as more sensitive information is stored in the cloud rather than in the home.
However, while this will inevitably hold true in some cases, the beauty of Justice Harlan’s approach is that not every investigative technique will require a warrant; rather, only acquiring certain categories of information will. In those cases where a warrant would be needed to obtain the sensitive information, many times the evidence already at the
government’s disposal can establish the requisite probable cause to obtain it.[305] Moreover, that people will store more sensitive information in the cloud also creates an opportunity for law enforcement because more incriminating information, both quantitatively and qualitatively, may potentially be acquired than there ever used to be.[306]
- It Will “Make a Crazy Quilt of the Fourth Amendment”[307]
It is a well-established principle that courts strive to provide stability and predictability so those subject to the law can conform their conduct to its contours.[308] In that vein, a likely criticism of Justice Harlan’s approach to the warrant requirement is that it would “make a crazy quilt of the Fourth Amendment.”[309] The thought is that law enforcement would always be uncertain of when the possible chilling effect is so great as to require a warrant, thus undermining legitimate law enforcement goals.[310]
The uncertainty resulting from balancing the chilling effect against the burden of obtaining a warrant would not remain in perpetuity. Because the potential chilling effect of the unfettered surveillance of transactional information directly correlates to its sensitivity,[311] legal arguments would accordingly shift from who holds the information (a possession-based approach) to the sensitivity of what it might reveal (a privacy-based approach). As more courts decide what types and aspects
of transactional information are sensitive enough to merit Fourth Amendment protection, the complained-of uncertainty would naturally diminish. Ultimately, the desired stability and predictability would inevitably emerge.
Undoubtedly, some new technologies will produce uncertainty until the Supreme Court examines them through the lens of the Fourth Amendment. This characteristic, however, is a feature of Justice Harlan’s approach, not a bug. Justice Harlan envisioned a context-dependent balancing test for determining when the Fourth Amendment’s warrant requirement applies to the government’s acquisition of information.[312] As society evolves, so too will technology’s capacity for invading privacy; our circumstances will not remain static. Justice Harlan’s approach works because it adapts to technological changes without requiring each generation to rewrite its property laws, let alone to do so in a consistent manner between jurisdictions. A jurisprudence that dispenses with the need to continually readjust our understanding of privacy by providing absolute certainty for all time betrays the principles underlying the Fourth Amendment.[313] Rather, the opposite—an approach that provides flexibility—is needed. Justice Harlan’s jurisprudence gives us just that, and the Supreme Court in Carpenter vindicated the wisdom of this approach.
Any resulting uncertainty would also not unduly burden the government’s investigative efforts. This approach would require the government to calculate the risk of obtaining the information without a warrant in light of any remaining uncertainty and decide whether to expend the associated costs. That is, the government would subject to no more of an obligation than any other party subject to a duty of care. On one hand, the government could choose to obtain the information through some other method of compulsory process[314] and risk suppression of the evidence[315] if it erroneously calculated the potential chilling effect. On the other hand, and more likely, the government, in those cases where uncertainty remains, would be a reasonable actor and pursue a warrant; that is, it would receive assurance from a neutral magistrate that the negative externalities are accounted for.[316]
The “reasonable expectation of privacy” test, as articulated in Justice Harlan’s Katz concurrence, has been quoted time and again as the framework by which courts measure whether the government’s conduct constitutes a Fourth Amendment search. Despite its widespread use, the test has received seemingly endless criticism that it is inadequate to protect privacy rights in the Information Age, in part due to its supposed hand in constitutionalizing the divide between content and transactional information. But, as the sensitivity of the latter becomes more analogous to that of the former, applying the test as Justice Harlan envisioned, just as the Carpenter Court did, would effectively balance individual privacy rights against legitimate law enforcement needs.
† Head de•novo Editor, Cardozo Law Review. J.D. Candidate (June 2020), Benjamin N. Cardozo School of Law; B.S., State University of New York (SUNY) Oneonta, 2012. I am indebted to the following individuals for their guidance throughout the writing process: Professor Ekow Yankah for serving as my Note Advisor and his support in exploring my intellectual passions; Peter Winn for planting the seed for this Note; Judge James Orenstein, Judge David Kirschner, and Professor Michael Pollack for their invaluable insights and advice; and the entire Cardozo Law Review staff, both this year and last, for their tireless work on my many drafts. Most of all, I must thank my parents, Karen and Artie; my brother, Scott; and my partner, Jacalyn, for their undying love and support, without which my law school journey would have gone over like a lead balloon.
[1] United States v. White, 401 U.S. 745, 786 (1971) (Harlan, J., dissenting).
[2] “The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause . . . .” U.S. Const. amend. IV.
[6] Id. See generally discussion infra Section I.D.
[7] See, e.g., Riley v. California, 573 U.S. 373 (2014); United States v. Jones, 565 U.S. 400 (2012); Kyllo v. United States, 533 U.S. 27 (2001); see also discussion infra Section I.D.
[8] Orin Kerr, When Does a Carpenter Search Start—and When Does It Stop?, Lawfare (July 6, 2018, 10:24 AM), https://www.lawfareblog.com/when-does-carpenter-search-start-and-when-does-it-stop [https://perma.cc/GZ2Z-HQNS] (discussing whether the search of an aggregated data set begins at acquisition or at access).
[9] See Carpenter, 138 S. Ct. at 2217 n.3.
[11] See infra text accompanying notes 85–89.
[12] See, e.g., Barry Friedman, Unwarranted: Policing Without Permission 219–25 (1st ed. 2017); Oren Bar-Gill & Barry Friedman, Taking Warrants Seriously, 106 Nw. U. L. Rev. 1609, 1610–11 (2012); Ricardo J. Bascuas, The Fourth Amendment in the Information Age, 1 Va. J. Crim. L. 481, 487–90 (2013); Steven M. Bellovin et al., It’s Too Complicated: How the Internet Upends Katz, Smith, and Electronic Surveillance Law, 30 Harv. J.L. & Tech. 1, 10 & n.40 (2016); Orin S. Kerr, Four Models of Fourth Amendment Protection, 60 Stan. L. Rev. 503, 504–05 (2007); Orin S. Kerr, The Case for the Third-Party Doctrine, 107 Mich. L. Rev. 561, 563–64 (2009); Alexander T. Nguyen, Here’s Looking at You, Kid: Has Face-Recognition Technology Completely Outflanked the Fourth Amendment?, 7 Va. J.L. & Tech. 2 (2002); Michael C. Pollack, Taking Data, 86 U. Chi. L. Rev. 77, 79 (2019); Michael W. Price, Rethinking Privacy: Fourth Amendment “Papers” and the Third-Party Doctrine, 8 J. Nat’l Security L. & Pol’y 247, 248, 262–64 (2016); Michael Vitiello, Katz v. United States: Back to the Future?, 52 U. Rich. L. Rev. 425 (2018); cf. Lucas Issacharoff & Kyle Wirshba, Restoring Reason to the Third Party Doctrine, 100 Minn. L. Rev. 985, 985–86 (2016).
[13] See Carpenter, 138 S. Ct. at 2226 (Kennedy, J., dissenting) (citing United States v. Thompson, 866 F.3d 1149 (10th Cir. 2017); United States v. Graham, 824 F.3d 421 (4th Cir. 2016) (en banc), rev’g 796 F.3d 332 (4th Cir. 2015); United States v. Carpenter, 819 F.3d 880 (6th Cir. 2016); United States v. Davis, 785 F.3d 498 (11th Cir. 2015) (en banc), rev’g in part 754 F.3d 1205 (11th Cir. 2014); In re Application of U.S. for Historical Cell Site Data, 724 F.3d 600 (5th Cir. 2013)).
[14] See Pollack, supra note 12, at 79 (noting the “somewhat schizophrenic fashion” of the “effort to adapt privacy and law enforcement to new technology”); see also Carpenter, 138 S. Ct. at 2241–46 (Thomas, J., dissenting); id. at 2247, 2261 (Alito, J., dissenting); id. at 2264–67 (Gorsuch, J., dissenting); .
[15] Olmstead v. United States, 277 U.S. 438, 473 (1928) (Brandeis, J., dissenting) (quoting Weems v. United States, 217 U.S. 349, 373 (1910)); see infra text accompanying notes 166–180. See generally discussion infra Section I.A.
[16] See discussion infra Section I.D.
[17] “Because no examination of an individual’s judicial philosophy is complete without a brief foray into his personal history,” see Stephen M. Dane, “Ordered Liberty” and Self-Restraint: The Judicial Philosophy of the Second Justice Harlan, 51 U. Cin. L. Rev. 545, 546 n.5 (1982), for a discussion of Justice Harlan’s life before his appointment to the Supreme Court.
[18] 389 U.S. 347, 361 (1967) (Harlan, J., concurring); Peter Winn, Katz and the Origins of the “Reasonable Expectation of Privacy” Test, 40 McGeorge L. Rev. 1, 7 (2009).
[20] Although there are overlapping concerns with the government’s intelligence-gathering activities, this Note will not address them except where applicable to the criminal investigations context.
[21] Justice Harlan’s grandfather, also John Marshall Harlan, was an Associate Justice of the Supreme Court from 1877–1911. Tinsley E. Yarbrough, John Marshall Harlan: Great Dissenter of the Warren Court vii (1992).
[22] See Weeks v. United States, 232 U.S. 383, 390 (1914) (discussing the maxim’s prominence and influence on Fourth Amendment jurisprudence); Friedman, supra note 12, at 132; Price, supra note 12, at 258; see also M. Blane Michael, Judge, U.S. Court of Appeals for the Fourth Circuit, Reading the Fourth Amendment: Guidance from the Mischief that Gave It Birth, Madison Lecture at the New York University School of Law (Oct. 20, 2009), in 85 N.Y.U. L. Rev. 905, 908–09 (2010); Barry Friedman & Orin Kerr, The Fourth Amendment, Nat’l Const. Ctr., https://constitutioncenter.org/interactive-constitution/amendments/amendment-iv [https://perma.cc/2VJR-BW95].
[23] See Carpenter v. United States, 138 S. Ct. 2206, 2213 (2018) (citing Riley v. California, 573 U.S. 373, 403 (2014)); Boyd v. United States, 116 U.S. 616, 625 (1886); Friedman, supra note 12, at 124–25; Laura K. Donohue, The Original Fourth Amendment, 83 U. Chi. L. Rev. 1181, 1250 (2016); Leonard W. Levy, Origins of the Fourth Amendment, 114 Pol. Sci. Q. 79, 79 (1999).
[24] See Carpenter, 138 S. Ct. at 2239 n.6 (Thomas, J., dissenting); Boyd, 116 U.S. at 625–26; see also Friedman, supra note 12, at 124–25, 131–33; Friedman & Kerr, supra note 22; Levy, supra note 23, at 82; Neil Richards, The Third-Party Doctrine and the Future of the Cloud, 94 Wash. U. L. Rev. 1441, 1449 (2017).
[25] John Adams, Abstract of the Argument For and Against the Writs of Assistance, in 2 Legal Papers of John Adams 134, 140 (L. Kinvin Wroth & Hiller B. Zobel eds., 1965) (quoting James Otis’s argument against writs of assistance); Michael, supra note 22, at 908; see Donohue, supra note 23, at 1250; see also Olmstead v. United States, 277 U.S. 438, 474 (1928) (Brandeis, J., dissenting).
[26] See Donohue, supra note 23, at 1269–71 (explaining the historical meaning of “unreasonable” as used in the Fourth Amendment).
[27] See Carpenter, 138 S. Ct. at 2239–40 (Thomas, J., dissenting); Riley, 573 U.S. at 403; Weeks, 232 U.S. at 390; Friedman, supra note 12, at 127–33; Donohue, supra note 23, at 1280–98, 1305–08; Michael, supra note 22, at 907; Price, supra note 12, at 250–58; Richards, supra note 24, at 1449.
[29] Boyd, 116 U.S. at 630; see Riley, 573 U.S. at 403; Berger v. New York, 388 U.S. 41, 58 (1967); see also Friedman, supra note 12, at 124–25; Donohue, supra note 23, at 1299–305; Michael, supra note 22, at 912; Christopher Slobogin, A Defense of Privacy as the Central Value Protected by the Fourth Amendment’s Prohibition on Unreasonable Searches, 48 Tex. Tech L. Rev. 143, 145–47 (2015).
[30] See Warden v. Hayden, 387 U.S. 294, 301 (1967); Michael, supra note 22, at 912; see also Friedman, supra note 12, at 120–21. But see Akhil Reed Amar, Fourth Amendment First Principles, 107 Harv. L. Rev. 757 (1994).
[31] See Judicial Act of 1789, ch. 20, § 14, 1 Stat. 73. This section of the Judiciary Act of 1789, commonly known as the All Writs Act, has subsequently been modified in form but not in substance. See 28 U.S.C. § 1651(a) (2012); Sarah Jeong, Judge James Orenstein Has Something to Say About the U.S. Government’s Decryption of iPhones, Vice News (Mar. 1, 2016, 3:30 PM), https://www.vice.com/en_us/article/pa4v97/judge-james-orenstein-has-something-to-say-about-the-us-governments-decryption-of-iphones [https://perma.cc/A4BL-WUZN].
[32] Orin S. Kerr, The Curious History of Fourth Amendment Searches, 2012 Sup. Ct. Rev. 67, 77 n.42 (2012); Slobogin, supra note 29, at 147.
[36] Id. at 732–33; Slobogin, supra note 29, at 147.
[39] See id.; see also Slobogin, supra note 29, at 147.
[40] See Samuel D. Warren & Louis D. Brandeis, The Right to Privacy, 4 Harv. L. Rev. 193, 195 (1890); Winn, supra note 18, at 1.
[41] The early twentieth century did, however, see an enlargement of remedies available for Fourth Amendment violations committed by the federal government. See, e.g., Weeks v. United States, 232 U.S. 383 (1914) (holding the “exclusionary rule” prohibited the introduction of unlawfully obtained evidence); see also Silverthorne Lumber Co. v. United States, 251 U.S. 385 (1920) (extending the exclusionary rule to derivatives of unlawfully obtained evidence).
[43] Id. at 455. The Court also considered whether such activity violated the Fifth Amendment. Id. See generally U.S. Const. amend. V (“No person . . . shall be compelled in any criminal case to be a witness against himself . . . .”).
[44] Olmstead, 277 U.S. at 464–66; see also Friedman, supra note 12, at 217; Kerr, supra note 32, at 81; Slobogin, supra note 29, at 147; Winn, supra note 18, at 1–2.
[45] Olmstead, 277 U.S. at 464–65; see also Kerr, supra note 32, at 81. Notably, the Court left room for Congress to protect the contents of phone conversations. Olmstead, 277 U.S. at 465–66. Congress did just that by enacting the Communications Act of 1934, which, in part, prohibited evidence obtained through warrantless wiretapping from being introduced at trial. Pub. L. No. 73-416, § 605, 48 Stat. 1064, 1103–04; see also Gina Stevens & Charles Doyle, Cong. Research Serv., 98-326, Privacy: An Overview of Federal Statutes Governing Wiretapping and Electronic Eavesdropping 3 (2012), https://fas.org/sgp/crs/intel/98-326.pdf [https://perma.cc/DP58-R428]; Richards, supra note 24, at 1460.
[46] Olmstead, 277 U.S. at 472–73 (Brandeis, J., dissenting).
The makers of our Constitution . . . recognized the significance of man’s spiritual nature, of his feelings and of his intellect. They knew that only a part of the pain, pleasure and satisfactions of life are to be found in material things. They sought to protect Americans in their beliefs, their thoughts, their emotions and their sensations. They conferred, as against the Government, the right to be let alone . . . . To protect that right, every unjustifiable intrusion by the Government upon the privacy of the individual, whatever the means employed, must be deemed a violation of the Fourth Amendment.
Id. at 478; see also Neil Richards, Intellectual Privacy: Rethinking Civil Liberties in the Digital Age 5 (2015) (discussing “intellectual privacy”); Julie E. Cohen, What Privacy Is For, 126 Harv. L. Rev. 1904, 1911 (2013).
[49] Olmstead, 277 U.S. at 475 (Brandeis, J., dissenting).
[50] Id. at 475–76 (arguing wiretapping invades the privacy of both the target and all others to whom they may speak); see also id. at 476 (“As a means of espionage, writs of assistance and general warrants are but puny instruments of tyranny and oppression when compared with wire-tapping.”).
[51] See Kerr, supra note 32, at 85; Price, supra note 12, at 258–59; see also David H. Hines, Note, Fourth Amendment Limitations on Eavesdropping and Wire-Tapping, 16 Clev.-Marshall L. Rev. 467, 469–71 (1967).
[55] Id. at 751. For an explanation of the capabilities of a “bug,” which On Lee’s acquaintance was wearing, and a wiretap, such as the one used in Olmstead, see Berger v. New York, 388 U.S. 41, 46–47 (1967).
[56] The transmitted conversation occurred on On Lee’s property, and he had consented to the informant’s entry, albeit under the guise of friendship. On Lee, 343 U.S. at 751–54.
[61] See id. at 509–12. Though it did not outright say so, the Silverman Court implicitly overruled Olmstead insofar as it held that verbal conversations were not protected by the Fourth Amendment because of their intangibility. See id. at 511; see also Hoffa v. United States, 385 U.S. 293, 301 (1966). The Supreme Court confirmed this notion two years later. See Wong Sun v. United States, 371 U.S. 471, 485 (1963); see also Berger v. New York, 388 U.S. 41, 52 (1967).
[62] See infra note 65. Although no decisions yet mentioned in this Section address the Fourth Amendment in terms of the sensitivity of what the surveillance could reveal, several concurring and dissenting opinions would have rested on such grounds. See, e.g., Silverman, 365 U.S. at 512–13 (Douglas, J., concurring); On Lee, 343 U.S. at 759 (Frankfurter, J., dissenting); id. at 762–65 (Douglas, J., dissenting); Goldman v. United States, 316 U.S. 129, 136–42 (1942) (Murphy, J., dissenting).
[65] Id. at 438–40; accord Osborn v. United States, 385 U.S. 323, 327 & n.4 (1966). The Lopez majority explained: “We think the risk that [Lopez] took in offering a bribe . . . fairly included the risk that the offer would be accurately reproduced in court . . . .” Lopez, 373 U.S. at 439. The Court further distinguished the case from previous decisions on the grounds that the recording was not obtained through an unlawful physical invasion, since the agent was invited into Lopez’s office to participate in the conversation. Id. at 438–40.
[66] See, e.g., Schmerber v. California, 384 U.S. 757 (1966) (holding intrusion into the human body ordinarily requires a search warrant, but taking a blood sample to test alcohol content falls under the “exigent circumstances” exception); Ker v. California, 374 U.S. 23 (1963) (incorporating the Fourth Amendment’s prohibition on unlawful searches and seizures into the Fourteenth Amendment’s Due Process Clause); Mapp v. Ohio, 367 U.S. 643 (1961) (holding the exclusionary rule applicable to state courts).
[69] See Winn, supra note 18, at 2 n.6 (explaining the political aftermath of Olmstead).
[71] Id. at 44, 56–57. For example, the statute required neither a showing of probable cause nor particularity in the authorizing court order. Id. at 58–59.
[72] Id. at 54–60, 64; see supra note 71.
[73] Berger, 388 U.S. at 44, 51–52.
[74] See id. at 56 (“By its very nature eavesdropping involves an intrusion on privacy that is broad in scope.”).
[78] Id. at 349–51, cert. granted, 386 U.S. 954 (1967); see also Winn, supra note 18, at 3–5.
[79] See Katz, 389 U.S. at 350–53.
[81] Id. at 351 (citations omitted).
[82] Id. at 353; see also id. at 362 n.* (Harlan, J., concurring).
[83] Id. at 354–56 (majority opinion).
[84] Id. at 357–58. The Court rejected the argument that the “search incident to arrest,” “hot pursuit,” or “consent” exceptions applied. Id. at 357–58 & nn.20–22. The Court also declined to create a new exception for public telephone booths. Id. at 358.
[85] See United States v. Jones, 565 U.S. 400, 405–06 (2012); Kyllo v. United States, 533 U.S. 27, 32–33 (2001); Amar, supra note 30, at 769 n.43.
[86] Katz, 389 U.S. at 361 (Harlan, J., concurring) (quoting 389 U.S. at 351 (majority opinion)).
[89] See Jones, 565 U.S. at 411–13; Winn, supra note 18, at 8–9; see also Alderman v. United States, 394 U.S. 165, 191–92 (1969) (Harlan, J., concurring and dissenting in part); cf. United States v. White, 401 U.S. 745, 780 (1971) (Harlan, J., dissenting) (“Katz added no new dimension to the law. At most it was a formal dispatch of Olmstead and the notion that such problems may usefully be resolved in the light of trespass doctrine . . . .”). Within a year, the Court adopted Justice Harlan’s framework as the test for determining applicability of the Fourth Amendment’s Warrant Clause in all contexts, not just for electronic communications. See Mancusi v. DeForte, 392 U.S. 364, 365–69 (1968); Nadine Strossen, Justice Harlan’s Enduring Importance for Current Civil Liberties Issues, from Marriage Equality to Dragnet NSA Surveillance, 61 N.Y.L. Sch. L. Rev. 331, 344 (2016–2017); Winn, supra note 18, at 7.
[90] Katz, 389 U.S. at 361–62 (Harlan, J., concurring).
[91] Id. The following year, Congress enacted the Wiretap Act as Title III of the Omnibus Crime Control and Safe Streets Act of 1968, Pub. L. No. 90-351, sec. 802, §§ 2510–20, 82 Stat. 197, 212–25 [hereinafter Wiretap Act] (codified as amended at 18 U.S.C. §§ 2510–2522 (2018)). Due to the sensitive nature of what phone conversations could reveal, the Wiretap Act created a statutory framework for the government to intercept the contents of wire and oral communications that not only complied with Berger and Katz but went above and beyond the Fourth Amendment’s requirements. E.g., Wiretap Act § 2518(3)(c) (requiring a judge to determine that “normal investigative procedures have been tried and have failed or reasonably appear to be unlikely to succeed if tried or to be too dangerous” before issuing a wiretap order); see United States v. U.S. Dist. Court, 407 U.S. 297, 302 (1972); S. Rep. No. 90-1097 (1968), as reprinted in 1968 U.S.C.C.A.N. 2112, 2113, 2153.
[92] See Jones, 565 U.S. at 405–06; Kyllo v. United States, 533 U.S. 27, 32–33 (2001).
[94] Id. at 746–47 (plurality opinion).
[95] The agent in the kitchen closet was there with the informant’s permission. Id. at 747.
[97] Id. One of these conversations occurred in White’s home, one in a restaurant, and two in the informant’s car. Id.
[98] Id. at 749, 751–53 (“If the law gives no protection to the wrongdoer whose trusted accomplice is or becomes a police agent, neither should it protect him when that same agent has recorded or transmitted the conversations which are later offered in evidence to prove the State’s case.” (citing Lopez v. United States, 373 U.S. 427 (1963))).
[99] Id. at 749–50 (citations omitted). See generally Hoffa v. United States, 385 U.S. 293 (1966) (holding the Fourth Amendment does not protect a misplaced belief that someone to whom wrongdoing is voluntarily disclosed will not reveal that wrongdoing to the government); Lewis v. United States, 385 U.S. 206 (1966) (declining to extend the warrant requirement to a government agent who conceals their identity to the defendant and purchases narcotics); Lopez v. United States, 373 U.S. 427 (1963) (see supra text accompanying notes 64–65); On Lee v. United States, 343 U.S. 747 (1952) (see supra text accompanying notes 55–57).
[101] Smith v. Maryland, 442 U.S. 735, 738 (1979).
[102] See Carpenter v. United States, 138 S. Ct. 2206, 2216 (2016).
[103] Smith, 442 U.S. at 742–43.
[105] Id. at 743 (quoting Brief for Petitioner at 6, Smith, 442 U.S. 735 (No. 78-5374) , 1979 WL 199743, at *6).
[108] Id. (citing United States v. Miller, 425 U.S. 435, 442–44 (1976); Couch v. United States, 409 U.S. 322, 335–36 (1973); United States v. White, 401 U.S. 745, 752 (1971) (plurality opinion); Hoffa v. United States, 385 U.S. 293, 302 (1966); Lopez v. United States, 373 U.S. 427 (1963)); see also supra text accompanying note 99. For a discussion of Smith’s holding and the Third-Party Doctrine’s roots in prior cases concerning undercover informants and third-party account records, see Kerr, The Case for the Third-Party Doctrine, supra note 12, at 566–69, and Richards, supra note 24, at 1474.
[109] See Smith, 442 U.S. at 748 (Stewart, J., dissenting) (“The numbers dialed from a private telephone—although certainly more prosaic than the conversation itself—are not without ‘content’ . . . [S]uch a list . . . easily could reveal the identities of the persons and the places called, and thus reveal the most intimate details of a person’s life.”); id. at 751 (Marshall, J., dissenting) (“[F]or those ‘extensive intrusions that significantly jeopardize [individuals’] sense of security . . . more than self-restraint by law enforcement officials is required.’ The use of pen registers . . . constitutes such an extensive intrusion. To hold otherwise ignores the vital role telephonic communication plays in our . . . relationships as well as the [constitutional] interests implicated by unfettered official surveillance. Privacy in placing calls is of value not only to those engaged in criminal activity.” (second and third alterations in original) (quoting White, 401 U.S. at 786 (Harlan, J., dissenting)) (citing Katz v. United States, 389 U.S. 347, 352 (1967))).
[110] Carpenter v. United States, 138 S. Ct. 2206, 2216 (2018) (citing Smith, 442 U.S. at 743–44; Miller, 425 U.S. at 443).
[113] “A beeper is a radio transmitter, usually battery operated, which emits periodic signals that can be picked up by a radio receiver.” Id. at 707 n.1 (quoting Knotts, 460 U.S. at 277).
[114] See Knotts, 460 U.S. at 277–80.
[115] See Karo, 468 U.S. at 708–11.
[116] Knotts, 460 U.S. at 281–82.
[117] Karo, 468 U.S. at 711–13.
[118] See id. at 715; Knotts, 460 U.S. at 281–85.
[119] Karo, 468 U.S. at 715 (quoting Knotts, 460 U.S. at 281).
[121] See id. at 29–30 (explaining the device “operate[d] somewhat like a video camera showing heat images”).
[123] Id. at 34–35. See generally supra Section I.A.
[124] Kyllo, 533 U.S. at 37. The government also argued the technology’s use was constitutional because it detected only the heat radiating from the home’s external surface. Id. at 35–37. The Court rejected this rationale as too “mechanical” and too analogous to the rationale rejected in Katz. Id.
[125] Id. at 38–39. See infra Section III.C for a critique of this rationale.
[126] Kyllo, 533 U.S. at 37–39.
[128] The U.S. Department of Justice also made a concerted effort to keep these issues out of the Court’s reach. See James Orenstein, I’m a Judge. Here’s How Surveillance Is Challenging Our Legal System., N.Y. Times (June 13, 2019), https://www.nytimes.com/2019/06/13/opinion/privacy-law-enforcment-congress.html [https://perma.cc/E22U-FBX5].
[129] See City of Ontario v. Quon, 560 U.S. 746 (2010).
[130] Id. at 756 (quoting O’Connor v. Ortega, 480 U.S. 709, 725 (1987) (plurality opinion); O’Connor, 480 U.S. at 732 (Scalia, J., concurring in the judgment)).
[131] See id. at 759 (citing Olmstead v. United States, 277 U.S. 438 (1928)).
[132] 565 U.S. 400 (2012), aff’g sub nom. Unites States v. Maynard, 615 F.3d 544 (D.C. Cir. 2010).
[133] Id. at 402. See generally supra text accompanying notes 111–119.
[134] United States v. Knotts, 460 U.S. 276, 278 (1983).
[135] See Jones, 565 U.S. at 429 n.10 (Alito, J., concurring in the judgment); Knotts, 460 U.S. at 278.
[136] See Knotts, 460 U.S. at 278.
[138] Compare Jones, 565 U.S. at 429 n.10 (Alito, J., concurring in the judgment) (“The beepers used in [Knotts and Karo] . . . had a limited range and could be lost if the police did not stay close enough. Indeed, in Knotts itself, officers lost the signal from the beeper, and only ‘with the assistance of a monitoring device located in a helicopter [was] the approximate location of the signal . . . picked up again about one hour later.’” (third and fourth alterations in original) (quoting Knotts, 460 U.S. at 277, 278)), with id. at 428 (“[N]ew ‘smart phones,’ which are equipped with a GPS device, permit more precise tracking. For example, when a user activates the GPS on such a phone, a provider is able to monitor the phone’s location and speed of movement . . . .”), and id. at 415 (Sotomayor, J., concurring) (“GPS monitoring generates a precise, comprehensive record of a person’s public movements . . . .”).
[139] Id. at 403 (majority opinion).
[141] Id. at 413; id. at 413 (Sotomayor, J., concurring); id. at 431 (Alito, J., concurring in the judgment).
[142] Id. at 404–05 (majority opinion).
[143] Id. at 406–07; cf. Winn, supra note 18, at 8–9; supra text accompanying note 89.
[145] Id. at 418–24 (Alito, J., concurring in the judgment).
[147] Id. at 426–27. However, Justice Alito did acknowledge that the Katz test came with its own complications. Id.
[150] See Orin S. Kerr, The Mosaic Theory of the Fourth Amendment, 111 Mich. L. Rev. 311, 313, 314 n.15 (2012).
[151] Jones, 565 U.S. at 413–14 (Sotomayor, J., concurring).
[154] Kerr, supra note 150, at 328 (citing Jones, 565 U.S. at 429–31 (Alito, J., concurring in the judgment)).
[155] See Jones, 565 U.S. at 415–16 (Sotomayor, J., concurring); see also Kerr, supra note 150, at 328. Justice Sotomayor also recognized that it might be necessary to reconsider the Third-Party Doctrine. Jones, 565 U.S. at 417. Her concurrence closely tracks Justice Harlan’s view of the Fourth Amendment protections. See discussion infra Section III.A.
[157] See generally id. at 382–85 (explaining the history of the “search incident to arrest” exception).
[159] Id. at 386; see also id. at 391–93.
[160] Id. at 386; id. at 404 (Alito, J., concurring in part and concurring in the judgment).
[161] Id. at 386 (majority opinion); id. at 404 (Alito, J., concurring in part and concurring in the judgment). More broadly, the Court declared that “any extension of [pre-digital] reasoning to digital data has to rest on its own bottom.” Brief for Petitioner at 38, Carpenter v. United States, 138 S. Ct. 2206 (2018) (No. 16-402) (alteration in original) (quoting Riley, 573 U.S. at 393 (majority opinion)).
[162] “[M]odern cell phones . . . are now such a pervasive and insistent part of daily life that the proverbial visitor from Mars might conclude they were an important feature of human anatomy.” Riley, 573 U.S. at 385; accord id. at 395.
[163] The Court considered data stored locally on the device itself as well as data stored in the cloud. See id. at 391–98.
[170] 18 U.S.C. § 2703(d) (2018); Carpenter, 138 S. Ct. at 2212.
[171] Carpenter, 138 S. Ct. at 2211.
[172] See id. at 2226 (Kennedy, J., dissenting) (citing United States v. Thompson, 866 F.3d 1149 (10th Cir. 2017); United States v. Graham, 824 F.3d 421 (4th Cir. 2016) (en banc), rev’g 796 F.3d 332 (4th Cir. 2015); United States v. Carpenter, 819 F.3d 880 (6th Cir. 2016); United States v. Davis, 785 F.3d 498 (11th Cir. 2015) (en banc), rev’g in part 754 F.3d 1205 (11th Cir. 2014); In re Application of U.S. for Historical Cell Site Data, 724 F.3d 600 (5th Cir. 2013)); id. at 2235 (Thomas, J., dissenting). But see Graham, 796 F.3d 332; Davis, 754 F.3d 1205; cf. Tracey v. State, 152 So. 3d 504 (Fla. 2014) (holding state constitution requires a warrant to acquire real-time CSLI); Commonwealth v. Augustine, 4 N.E.3d 846 (Mass. 2014) (holding state constitution requires a warrant to acquire historical CSLI); State v. Earls, 70 A.3d 630 (N.J. 2013) (holding state constitution requires a warrant to acquire all CSLI).
[173] Carpenter, 138 S. Ct. at 2216–17 (majority opinion) (quoting Smith v. Maryland, 442 U.S. 735, 743 (1979)).
[175] Id. at 2221. In essence, the Court held that the government performs a Fourth Amendment search of an individual when it uses compulsory process to acquire a third party’s business records containing transactional information that reveals the history of that individual’s movements. Id. at 2224 (Kennedy, J., dissenting); see also id. at 2247 (Alito, J., dissenting).
[176] Id. at 2218–19 (majority opinion).
[179] Id. at 2217–20; see also Opinion Announcement at 6:30, Carpenter, 138 S. Ct. 2206 (No. 16-402), https://www.oyez.org/cases/2017/16-402 [https://perma.cc/3LD9-5M5X] (“In light of the deeply revealing nature of CSLI, its depth, breadth and comprehensive reach and the inescapable and automatic nature of its collection[,] the fact that such information is gathered by a third-party does not make it any less deserving of Fourth Amendment protection.”).
[180] Carpenter, 138 S. Ct. at 2220; see, e.g., United States v. Contreras, 905 F.3d 853, 857 (5th Cir. 2018) (IP addresses obtained from an Internet service provider because they “had no bearing on any person’s day-to-day movement”); United States v. Oakes, 320 F. Supp. 3d 956, 961 (M.D. Tenn. 2018) (CSLI of phone for which defendant denied “ownership, possession, control, use, and exclusion of others”); United States v. Lightfoot, No. 17-0274, 2018 WL 4376509, at *5–6 (W.D. La. Aug. 30, 2018) (utility records), report and recommendation adopted, 2018 WL 4374196 (W.D. La. Sept. 13, 2018); United States v. Kay, No. 17-CR-16, 2018 WL 3995902 (E.D. Wis. Aug. 21, 2018) (pole cameras), adopting report and recommendation, 2018 WL 4375183 (E.D. Wis. Apr. 23, 2018); Cryer v. Idaho Dep’t of Labor, No. 1:16-cv-00526-BLW, 2018 WL 3636529, at *1 & n.1 (D. Idaho July 30, 2018) (information from a cellular service provider related to his IP address and cell phone number); see also infra note 236; cf. Andres v. State, 254 So. 3d 283, 297 & n.7 (Fla. 2018) (per curiam) (real-time CSLI obtained through use of cell-site simulator where it was used by police to locate defendant for purpose of executing search warrant for defendant’s body, home, and van). But see State v. Sylvestre, 254 So. 3d 986, 991 (Fla. Dist. Ct. App. 2018) (extending Carpenter’s warrant requirement to use of cell-site simulator); cf. Naperville Smart Meter Awareness v. City of Naperville, 900 F.3d 521, 525–29 (7th Cir. 2018) (holding city’s collection of electricity data constituted a search where the city installed in every home a smart electricity meter that recorded and saved consumption every fifteen minutes, but that such a search was reasonable).
[181] See Carpenter, 138 S. Ct. at 2223–24 (Kennedy, J., dissenting); id. at 2235–36 (Thomas, J., dissenting); id. at 2247 (Alito, J., dissenting).
[182] Id. at 2217 (majority opinion); cf. infra note 236. But see Carpenter, 138 S. Ct. at 2220.
[183] See 18 U.S.C. § 3127(3)–(4) (2018) (defining “pen register” and “trap and trace device,” respectively); United States v. N.Y. Tel. Co., 434 U.S. 159, 161 n.1 (1977).
[184] Cf. supra text accompanying note 47.
[185] See generally supra text accompanying notes 145–155.
[186] See generally supra text accompanying notes 2–5, 166–179.
[187] Carpenter, 138 S. Ct. at 2217 (quoting United States v. Jones, 565 U.S. 400, 415 (2012) (Sotomayor, J., concurring)).
[188] Id. at 2210 (quoting Riley v. California, 573 U.S. 373, 403 (2014)); Boyd v. United States, 116 U.S. 616, 630 (1886); see also Riley, 573 U.S. at 403 (“The fact that technology now allows an individual to carry such information in his hand does not make the information any less worthy of the protection for which the Founders fought.”); United States v. Warshak, 631 F.3d 266, 285 (6th Cir. 2010) (“[T]he Fourth Amendment must keep pace with the inexorable march of technological progress, or its guarantees will wither and perish.” (citing Kyllo v. United States, 533 U.S. 27, 34 (2001))); Brief for Petitioner, supra note 161, at 38 (“Equating a comprehensive digital repository of cell phone location records with a few days of dialed telephone numbers or even several months’ worth of canceled checks ‘is like saying a ride on horseback is materially indistinguishable from a flight to the moon.’ Both are records in the possession of a third party, ‘but little else justifies lumping them together.’” (quoting Riley, 573 U.S. at 393)).
[189] This Part’s descriptions of technical concepts are high-level, with some deeper technical information and variables purposely simplified or omitted. For a more in-depth discussion than this Note will provide on how the Internet renders the distinction between content and transactional information inappropriate, see Bellovin et al., supra note 12.
[190] According to data compiled by the National Telecommunications and Information Administration (NTIA), 90.8% of American Internet users use the Internet for email as of November 2017. Digital Nation Data Explorer, Nat’l Telecomms. & Info. Admin., https://www.ntia.doc.gov/data/digital-nation-data-explorer [https://perma.cc/DZ7X-D5Y2].
[191] Orin S. Kerr, Applying the Fourth Amendment to the Internet, 62 Stan. L. Rev. 1005, 1023 (2010); Heinz Tschabitscher, Get Important Email Info by Viewing the Entire Header, Lifewire, https://www.lifewire.com/what-is-an-email-header-1171127 [https://perma.cc/YPB6-NGAW] (last updated Aug. 19, 2019); U.S. Dep’t of Justice, Searching and Seizing Computers and Obtaining Electronic Evidence in Criminal Investigations 152 (2009) [hereinafter CCIPS Manual], https://www.justice.gov/sites/default/files/criminal-ccips/legacy/2015/01/14/ssmanual2009.pdf [https://perma.cc/RH2H-3DAG].
[192] Kerr, supra note 191, at 1019–20; Matthew J. Tokson, The Content/Envelope Distinction in Internet Law, 50 Wm. & Mary L. Rev. 2105, 2110–11 (2009); Tschabitscher, supra note 191. This Note uses the phrase “related to addressing” because whether this information is content or transactional information depends on where and when in the transmission process that question is asked. See Bellovin et al., supra note 12, at 61–64. Because the courts to face this question have mistakenly conflated header information—which is actually contained within the body of the email—with third-party addressing information, id. at 63, this Note proceeds under that same assumption.
[193] Tokson, supra note 192, at 2127. An IP address is a numerical identifier assigned to a computer to facilitate the sending and receiving of data between computers. DNS: The Magic that Translates Website Names into IP Addresses, WhatIsMyIPAddress.com, [hereinafter DNS] https://whatismyipaddress.com/dns [https://perma.cc/E25G-FRL6]; Tim Fisher, What Is an IP Address?, Lifewire, https://www.lifewire.com/what-is-an-ip-address-2625920 [https://perma.cc/HLM9-Z2U8] (last updated July 22, 2019); Nadeem Unuth, What IP Means and How It Works, Lifewire, https://www.lifewire.com/internet-protocol-explained-3426713 [https://perma.cc/DP6V-VWR6] (last updated Sept. 3, 2019); see also United States v. Forrester, 512 F.3d 500, 510 n.5 (9th Cir. 2008). For a discussion of the different types of IP addresses and their purposes, see Fisher, supra.
[194] Tokson, supra note 192, at 2127; Tschabitscher, supra note 191.
[195] See, e.g., United States v. Warshak, 631 F.3d 266, 285–88 (6th Cir. 2010). See generally Ex parte Jackson, 96 U.S. 727, 732–37 (1878); supra text accompanying notes 33–39.
[196] Generally, all computers on a single network are connected to a router, through which all inter-computer communications flow and which ensures a message is sent to the correct computer by routing the data based on the IP address of the intended recipient. Multiple routers can be interconnected to facilitate data transmission between individual networks. Countless networks exist in the world at any time, and they are continually created and decommissioned. This renders it unfeasible for an individual network’s administrator to manually connect her network to all others simultaneously. ISPs bridge this gap by connecting its customers’ routers to its own network of routers and, in turn, connecting its network to those of other ISPs. See Unuth, supra note 193.
[197] Warshak, 631 F.3d at 285–86.
[198] See Forrester, 512 F.3d at 509–11; In re Application of the U.S. for an Order Authorizing the Use of a Pen Register, 396 F. Supp. 2d 45, 48 (D. Mass. 2005).
[199] See Forrester, 512 F.3d at 510–11.
[200] See Warshak, 631 F.3d at 287–88 (declining to extend the Third-Party Doctrine to emails stored by an ISP); Forrester, 512 F.3d at 510. See generally Jackson, 96 U.S. 727; supra text accompanying notes 34–39.
[201] Tokson, supra note 192, at 2130; Tschabitscher, supra note 191; CCIPS Manual, supra note 191, at 152–53.
[202] See Brief for Petitioner, supra note 161, at 46–47 (“[I]f . . . the government [is] correct that Smith and Miller ‘resolve this case’ because ‘“a person has no legitimate expectation of privacy in information he voluntarily turns over to third parties,”’ there is no way to distinguish emails—or any other [sensitive information]—from CSLI.” (quoting Brief for the United States in Opposition at 14–15, Carpenter v. United States, 138 S. Ct. 2206 (2018) (No. 16-402), 2017 WL 3575179, at *14–15)).
[203] 18 U.S.C. § 2510(8) (2018); see Optiver, Austl. Pty. Ltd & Anor. v. Tibra Trading Pty. Ltd & Ors., No. C 12 -80242 EJD (PSG), 2013 WL 256771, at *2–3 (N.D. Cal. Jan. 23, 2013); In re Application, 396 F. Supp. 2d at 48; H.R. Rep. No. 107-236(I), at 53 (2001); CCIPS Manual, supra note 191, at 152–53; see also Forrester, 512 F.3d at 511; Kerr, supra note 191, at 1023; Tokson, supra note 192, at 2130.
[204] Katz v. United States, 389 U.S. 347, 361 (1967) (Harlan, J., concurring).
[206] For data regarding Americans’ most-conducted online activities, see Digital Nation Data Explorer, supra note 190.
[207] People often use “the Internet” and “the Web” interchangeably, but they are not the same. The Web is just one of many ways that information is shared over the Internet. Paul Gil, Internet vs. Web: What’s the Difference?, Lifewire, https://www.lifewire.com/difference-between-the-internet-and-the-web-2483335 [https://perma.cc/Z26W-PGTT] (last updated July 27, 2019).
[208] A user typically “browses” the Web by either entering a Web address into their browser or by clicking a link that brings them to a new location. See Scott Orgera, What is a Web Browser?, Lifewire, https://www.lifewire.com/what-is-a-browser-446234 [https://perma.cc/LVA2-G64Q] (last updated May 26, 2019).
[209] Boyd v. United States, 116 U.S. 616, 630 (1886).
[210] What Is the Difference Between Webpage, Website, Web Server, and Search Engine?, MDN web docs, https://developer.mozilla.org/en-US/docs/Learn/Common_questions/Pages_sites_servers_and_search_engines [https://perma.cc/26RX-2B9A] (last updated Aug. 6, 2019, 7:31 PM).
[212] Id.; How the Web Works, MDN web docs, https://developer.mozilla.org/en-US/docs/Learn/Getting_started_with_the_web/How_the_Web_works [https://perma.cc/MA94-3Q5A] (last updated May 18, 2019, 11:02 AM).
[213] See supra note 196. See generally supra note 193.
[214] See DNS, supra note 193; Chris Gonyea, DNS: Why It’s Important and How It Works, Oracle Dyn (Aug. 9, 2018), https://dyn.com/blog/dns-why-its-important-how-it-works [https://perma.cc/284L-WA3F].
For example, the URL “cardozolawreview.com/de-novo” identifies the web page for de•novo, the Cardozo Law Review’s online companion, on the Cardozo Law Review website. The domain name is “cardozolawreview.com,” which corresponds to the web server on which the website lives and is easier for a human to remember than that web server’s IP address. The file displayed in the browser is a document called “de-novo.” Thus, the full URL identifies the de•novo page’s exact location on the web server, or its file path.
URLs can be quite complex and may contain much more information than is described here. For a more in-depth analysis of the structure and nuances of URLs and the problems they pose in the context of electronic surveillance, see Bellovin et al., supra note 12, at 64–67, 71–72.
[215] DNS, supra note 193; Gonyea, supra note 214. For a deeper account of how DNS works, see DNS, supra note 193, and Matt Torrisi, How Does the Domain Name System (DNS) Actually Work?, Oracle Dyn (Sept. 19, 2017), https://dyn.com/blog/how-does-the-domain-name-system-dns-actually-work [https://perma.cc/9EW6-Z4HH].
[216] See A Few Good Reasons to Switch Your DNS Server, WhatIsMyIPAddress.com, https://whatismyipaddress.com/switch-dns [https://perma.cc/Y6GG-RQ7G].
[217] This information is then stored on the user’s computer to skip this step the next time they visit the website. See Gonyea, supra note 214.
[218] How the Web Works, supra note 212.
[219] All information sent over the Internet, whether it be email, a webpage, audio, and the like, is broken into small chunks, or packets, by the sender and is reassembled by the receiver. See, e.g., Nadeem Unuth, TCP (Transmission Control Protocol) Explained, Lifewire, https://www.lifewire.com/tcp-transmission-control-protocol-3426736 [https://perma.cc/3X6J-WPEG] (last updated June 23, 2018). All packets have two sections: the data payload, i.e., the content, and an IP header, i.e., the transactional information that tells a router where to send the packet. Unuth, supra note 193.
[220] CCIPS Manual, supra note 191, at 120–21; see, e.g., Fred Von Lohmann, Subpoenas and Your Privacy, Elec. Frontier Found. (Feb. 4, 2006), https://www.eff.org/deeplinks/2006/02/subpoenas-and-your-privacy [https://perma.cc/ABN7-XR79] (“Google, for example, has confirmed that if given an IP address, it can produce a list of every Google search query ever sent from it.”); see also Richards, supra note 48, at 5.
[221] Tim Fisher, What Are Cookies on a Computer?, Lifewire, https://www.lifewire.com/web-browser-cookies-3483129 [https://perma.cc/CCY9-Y88D] (last updated Aug. 12, 2019).
[223] See Google Mktg. Platform, https://marketingplatform.google.com/about [https://perma.cc/T6UX-8288].
[228] See Bellovin et al., supra note 12, at 72–73; Upturn, What ISPs Can See: Clarifying the Technical Landscape of the Broadband Privacy Debate 7 (2016), https://www.teamupturn.org/static/reports/2016/what-isps-can-see/files/Upturn%20-%20What%20ISPs%20Can%20See%20v.1.0.pdf [https://perma.cc/5GW3-9J6D]; cf. Von Lohmann, supra note 220.
[229] See 18 U.S.C. § 3123(a) (2018).
[231] Although users can disable cookies on their web browsers, see Fisher, supra note 221, a website operator can require cookies be enabled in order to view the content on webpages, see Fact and Fiction: The Truth About Browser Cookies, Lifehacker (Feb. 1, 2010, 12:00 PM), https://lifehacker.com/fact-and-fiction-the-truth-about-browser-cookies-5461114 [https://perma.cc/4T7A-3WCH].
[232] See Upturn, supra note 228, at 6–8.
[233] Data collected by the NTIA shows that over seventy-five percent of all Americans, and nearly eighty percent of Americans at least fifteen years old, use the Internet in some way. See Digital Nation Data Explorer, supra note 190; cf. Carpenter v. United States, 138 S. Ct. 2206, 2220 (2018) (“[C]ell phones and the services they provide are ‘such a pervasive and insistent part of daily life’ that carrying one is indispensable to participation in modern society.” (quoting Riley v. California, 573 U.S. 373, 385 (2014))).
[234] See Carpenter, 138 S. Ct. at 2217–19, 2217 n.3; see also United States v. Jones, 565 U.S. 400, 415 (2012) (Sotomayor, J., concurring) (“[A]t the very least, ‘longer term GPS monitoring in investigations of most offenses impinges on expectations of privacy.’” (quoting Jones, 565 U.S. at 430 (Alito, J., concurring in the judgment))).
[235] Olmstead v. United States, 277 U.S. 438, 478 (1928) (Brandeis, J., dissenting).
[236] This example was provided in Upturn, supra note 228, at 7.
[237] See Carpenter, 138 S. Ct. at 2217 (quoting Jones, 565 U.S. at 415 (Sotomayor, J., concurring)); see also Riley, 573 U.S. at 395–96. Notably, the courts to face the question of the Fourth Amendment’s application to IP addresses post-Carpenter—the same courts that erroneously turned cases like Smith into wholesale doctrine—have held that, despite the potentially sensitive nature of IP addresses, a user categorically cannot have a reasonable expectation of privacy in their Web-browsing activity. According to those courts, this is because an IP address is transactional and addressing information, more akin to the phone records in Smith than the CSLI in Carpenter. See, e.g., United States v. Contreras, 905 F.3d 853, 857 (5th Cir. 2018); United States v. Gregory, No. 8:18CR139, 2018 WL 6427871, at *1–2 (D. Neb. Dec. 7, 2018); United States v. Rosenow, No. 17CR3430 WQH, 2018 WL 6064949, at *10–11 (S.D. Cal. Nov. 20, 2018); United States v. Monroe, 350 F. Supp. 3d 43, 48–49 (D.R.I. 2018); United States v. Westley, No. 3:17-CR-171 (MPS), 2018 WL 3448161, at *6–7, *14, *6 n.4 (D. Conn. July 17, 2018); United States v. Tolbert, 326 F. Supp. 3d 1211, 1224–25 (D.N.M. 2018), reconsideration denied, No. 14-3761 JCH, 2019 WL 2931659 (D.N.M. July 7, 2019); cf. Cryer v. Idaho Dep’t of Labor, No. 1:16-cv-00526-BLW, 2018 WL 3636529, at *1 & n.1 (D. Idaho July 30, 2018). But cf. United States v. Loera, 333 F. Supp. 3d 172, 180 (E.D.N.Y. 2018).
Most courts to face the question before Carpenter ruled similarly. See, e.g., United States v. Ulbricht, 858 F.3d 71, 96–98 (2d Cir. 2017), cert. denied, 138 S. Ct. 2708 (2018); United States v. Kearney, 672 F.3d 81 (1st Cir. 2012); United States v. Hammalian, No. 2:17-cr-00070, 2018 WL 1951201, at *3–4 (D. Vt. Apr. 24, 2018).
[238] Worldwide Broadband Speed League 2019, Cable, https://cable.co.uk/broadband/speed/worldwide-speed-league [https://perma.cc/2ZHX-PQFF]; Alex Cranz, How Chip Makers Are Circumventing Moore’s Law to Build Super-Fast CPUs of Tomorrow, Gizmodo (Dec. 28, 2018, 12:35 PM), https://gizmodo.com/how-chip-makers-are-circumventing-moores-law-to-build-s-1831268322 [https://perma.cc/9JRC-HH8W].
[239] See, e.g., Robert Kyncl, The Inside Story of How Netflix Transitioned to Digital Video After Seeing the Power of YouTube, Vox: Recode (Sept. 13, 2017, 6:15 AM), https://www.vox.com/2017/9/13/16288364/streampunks-book-excerpt-youtube-netflix-pivot-video [https://perma.cc/TNB9-L4KS].
[240] See generally Internet of Things, Lexico, https://www.lexico.com/en/definition/internet_of_things [https://perma.cc/3YJ4-A664] (“The interconnection via the Internet of computing devices embedded in everyday objects, enabling them to send and receive data.”).
[241] Andreas Jacobsson, On Privacy and Security in Smart Homes, Medium (June 14, 2016), https://medium.com/@iotap/on-privacy-and-security-in-smart-homes-543f62aa9917 [https://perma.cc/4DGJ-NAGK].
[242] See id.; Note, If These Walls Could Talk: The Smart Home and the Fourth Amendment Limits of the Third Party Doctrine, 130 Harv. L. Rev. 1924, 1924 (2017); see also Andreas Jacobsson, IoT, Security and Privacy, Medium (June 14, 2016), https://medium.com/@iotap/internet-of-things-security-and-privacy-78bc0a41881b [https://perma.cc/W6Z5-7LRE].
[243] See Rani Molla, Mary Meeker’s 2018 Internet Trends Report: All the Slides, Plus Analysis, Vox: Recode (May 30, 2018, 12:37 PM), https://www.vox.com/2018/5/30/17385116/mary-meeker-slides-internet-trends-code-conference-2018 [https://perma.cc/KT6R-CFJQ] (“The Echo’s installed base in the U.S. grew from 20 million in the third quarter of 2017 to more than 30 million in the fourth quarter.”).
[244] For a discussion of how voice-controlled assistants work, including what they record and what they transmit to third parties, see Note, supra note 242, at 1939–41. See also Jay Stanley, The Privacy Threat from Always-On Microphones like the Amazon Echo, ACLU (Jan. 13, 2017, 10:15 AM), https://www.aclu.org/blog/privacy-technology/privacy-threat-always-microphones-amazon-echo [https://perma.cc/Z8YT-CTKE].
[245] Cf. Carpenter v. United States, 138 S. Ct. 2206, 2220 (2018).
[247] Boyd v. United States, 116 U.S. 616, 630 (1886).
Use of this device can allow companies . . . to create a comprehensive profile of the user and her activities, including . . . her health profile (health monitoring apps), whereabouts (calendar), activities (to-do lists), political leanings (which news sites she frequents), and even possibly her innermost thoughts (think of the one-off Google or WebMD searches you would prefer not to broadcast).
Note, supra note 242, at 1940–41; see also Grace Manning, Alexa: Can You Keep a Secret? The Third-Party Doctrine in the Age of the Smart Home, 56 Am. Crim. L. Rev. Online 25 (2019); Brief for Petitioner, supra note 161, at 45–46.
[249] Elizabeth Dwoskin, Amazon Is Selling Facial Recognition to Law Enforcement—For a Fistful of Dollars, Wash. Post (May 22, 2018), https://www.washingtonpost.com/news/the-switch/wp/2018/05/22/amazon-is-selling-facial-recognition-to-law-enforcement-for-a-fistful-of-dollars [https://perma.cc/F73F-XBPT]; see also Kate Fazzini, Amazon’s Facial Recognition Service Is Being Used to Scan Mugshots, But It’s Also Used to Track Innocuous Things like Soccer Balls, CNBC (Dec. 6, 2018, 2:29 PM), https://www.cnbc.com/2018/12/06/how-amazon-rekognition-works-and-what-its-used-for.html [https://perma.cc/9DM4-JKQH].
[250] Specifically, Amazon had licensed the software to law enforcement agencies in Oregon and Florida. See Dwoskin, supra note 249; Fazzini, supra note 249. A 2016 report by the Georgetown Law Center on Privacy and Technology identified at least five major police departments that have bought or had plans to buy real-time facial recognition technology. Georgetown Law Ctr. on Privacy & Tech., The Perpetual Line-Up: Unregulated Police Face Recognition in America 27 (2016) [hereinafter CPT Report], https://www.perpetuallineup.org/sites/default/files/2016-12/The%20Perpetual%20Line-Up%20-%20Center%20on%20Privacy%20and%20Technology%20at%20Georgetown%20Law%20-%20121616.pdf [https://perma.cc/K3LL-VMHG]; see also New ACLU Report Reveals Alarming Growth of AI Video Surveillance Technologies, ACLU (June 13, 2019), https://www.aclu.org/press-releases/new-aclu-report-reveals-alarming-growth-ai-video-surveillance-technologies [https://perma.cc/SYL7-8N7S]. Additionally, New York State’s transportation plan includes facial recognition technology at bridge and tunnel crossings, airports, and transit hubs by 2020. See Press Release, MTA, Governor Cuomo Announces Transformational Plan to Reimagine New York’s Bridges and Tunnels for 21st Century (Oct. 5, 2016), http://www.mta.info/news-governor-cuomo-bridges-and-tunnels-led-lights-open-road-tolling-automatic-tolling/2016/10/05 [https://perma.cc/Y5N8-N765].
[251] Fazzini, supra note 249.
[252] See, e.g., CPT Report, supra note 250, at 1; Fazzini, supra note 249.
[253] See Mariko Hirose, Privacy in Public Spaces: The Reasonable Expectation of Privacy Against the Dragnet Use of Facial Recognition Technology, 49 Conn. L. Rev. 1591, 1594 (2017); see also Press Release, supra note 250.
[254] See supra text accompanying notes 172–179; see also Nguyen, supra note 12, ¶¶ 45–51.
[255] Senators Roy Blunt of Missouri and Brian Schatz of Hawaii recently introduced the Commercial Facial Recognition Privacy Act of 2019, which would prohibit covered entities “from using facial recognition technology to identify or track an end user without obtaining the affirmative consent of the end user.” S. 847, 116th Cong. pmbl. (as introduced in the Senate, Mar. 14, 2019). The proposed bill, however, explicitly exempts federal and state governments and agencies from its limitations. Id. § 2(3)(B). Additionally, Representatives Elijah Cummings of Maryland and Jim Jordan of Ohio had reportedly planned to introduce a bipartisan bill that “could include issuing a pause on the federal government’s acquisition of new facial recognition technology,” but Representative Cummings passed away before the bill was finished. Shirin Ghaffary, How Facial Recognition Became the Most Feared Technology in the U.S., Vox: Recode (Aug. 9, 2019, 4:00 PM), https://www.vox.com/recode/2019/8/9/20799022/facial-recognition-law [https://perma.cc/S74E-6JCS]; Khari Johnson, Facial Recognition Regulation Is Surprisingly Bipartisan, VentureBeat (Nov. 11, 2019, 5:08 AM), https://venturebeat.com/2019/11/11/facial-recognition-regulation-is-surprisingly-bipartisan [https://perma.cc/FBA2-YRLG]. Nevertheless, some municipalities have taken notable steps to limit government agencies’ use of facial recognition technology. San Francisco and Oakland, California, and Somerville, Massachusetts, have banned its use by all municipal agencies, including law enforcement, and other cities and states are considering similar bans. See Ghaffary, supra; Jeffrey N. Rosenthal & Huaou Yan, Coming Face-to-Face with Facial Recognition Technology, Law.com: The Legal Intelligencer (July 29, 2019, 1:05 PM), https://www.law.com/thelegalintelligencer/2019/07/29/coming-face-to-face-with-facial-recognition-technology [https://perma.cc/NVK5-LN57].
[256] See Fazzini, supra note 249; Brad Smith, Facial Recognition: It’s Time for Action, Microsoft: On the Issues (Dec. 6, 2018), https://blogs.microsoft.com/on-the-issues/2018/12/06/facial-recognition-its-time-for-action [https://perma.cc/7XRF-7CGX].
[257] Cf. Carpenter v. United States, 138 S. Ct. 2206, 2220 (2018) (“Our decision today is a narrow one . . . . We do not . . . call into question conventional surveillance techniques and tools, such as security cameras . . . .”).
[258] See, e.g., Friedman, supra note 12, at 219–25; Strossen, supra note 89, at 344; cf. Kyllo v. United States, 533 U.S. 27, 32–33 (2001) (“In assessing when a search is not a search, we have applied somewhat in reverse the principle first enunciated in [Katz].”). Admittedly, some of the Court’s decisions not in the context of electronic communications or other modern technologies also lend support to this notion. See Friedman, supra note 12, at 219–28.
[259] See, e.g., Bascuas, supra note 12; Bellovin et al., supra note 12; Price, supra note 12; Issacharoff & Wirshba, supra note 12; see also Pollack, supra note 12.
[260] John M. Harlan, Thoughts at a Dedication: Keeping the Judicial Function in Balance, 49 A.B.A. J. 943, 944 (1963); see Dane, supra note 17, at 547, 565–66; Tinsley E. Yarbrough, Mr. Justice Harlan: Reflections of a Biographer, 36 N.Y.L. Sch. L. Rev. 223, 223 (1991); see also Henry J. Bourguignon, The Second Mr. Justice Harlan: His Principles of Judicial Decision Making, 1979 Sup. Ct. Rev. 251, 272; Philip B. Heymann, in John Marshall Harlan II, Associate Justice of the Supreme Court 1955–1971: Remembrances by His Law Clerks (Norman Dorsen & Amelia Ames Newcomb, eds., 2001), reprinted in 27 J. Sup. Ct. Hist. 138, 152 (2002) [hereinafter Remembrances] (“In Katz v. United States, he demanded to know what made an expectation of privacy in a phone booth ‘reasonable,’ not satisfied that he instinctively recoiled at secret monitoring of such a conversation.”). But cf. Poe v. Ullman, 367 U.S. 497, 524 (1961) (Harlan, J., dissenting).
[261] Yarbrough, supra note 260, at 223, 232. See generally Stare decisis, Black’s Law Dictionary (11th ed. 2019).
[262] See Harlan, supra note 260, at 944; Bourguignon, supra note 260, at 277–81; see also Toni J. Ellington, Comment, Ruth Bader Ginsburg and John Marshall Harlan: A Justice and Her Hero, 20 U. Haw. L. Rev. 797, 800 (1998); Catherine Hancock, Warrants for Wearing a Wire: Fourth Amendment Privacy and Justice Harlan’s Dissent in United States v. White, 79 Miss. L.J. 35, 54–56 (2009); Remembrances, supra note 260, at 152.
[263] Katz v. United States, 389 U.S. 347, 361 (1967) (Harlan, J., concurring); see Hancock, supra note 262, at 54–56; Orin S. Kerr, Katz Has Only One Step: The Irrelevance of Subjective Expectations, 82 U. Chi. L. Rev. 113, 124 (2015). Justice Harlan wrote:
I join the opinion of the Court, which I read to hold only (a) that an enclosed telephone booth is an area where, like a home, and unlike a field, a person has a constitutionally protected reasonable expectation of privacy; (b) that electronic as well as physical intrusion into a place that is in this sense private may constitute a violation of the Fourth Amendment; and (c) that the invasion of a constitutionally protected area by federal authorities is, as the Court has long held, presumptively unreasonable in the absence of a search warrant.
As the Court’s opinion states, “the Fourth Amendment protects people, not places.” The question, however, is what protection it affords to those people. Generally, as here, the answer to that question requires reference to a “place.” My understanding of the rule that has emerged from prior decisions is that there is a twofold requirement, first that a person have exhibited an actual (subjective) expectation of privacy and, second, that the expectation be one that society is prepared to recognize as “reasonable.” Thus a man’s home is, for most purposes, a place where he expects privacy, but objects, activities, or statements that he exposes to the “plain view” of outsiders are not “protected” because no intention to keep them to himself has been exhibited. On the other hand, conversations in the open would not be protected against being overheard, for the expectation of privacy under the circumstances would be unreasonable.
Katz, 389 U.S. at 360–61 (Harlan, J., concurring) (citations omitted).
[264] See Remembrances, supra note 260, at 158 (“[H]e never suggested adding or retaining lines that might carry rhetorical force but did not stand up to careful analysis.”); see also Yarbrough, supra note 260, at 226.
[265] Katz, 389 U.S. at 361 (Harlan, J., concurring).
[266] Winn, supra note 18, at 12; see Katz, 389 U.S. at 361 (Harlan, J., concurring); Hancock, supra note 262, at 56–57 (“Harlan used these words as a framework for rejecting the . . . argument that privacy can exist only in areas in which the speaker has a private interest in the premises, never in a public area.”); see also Katz, 389 U.S. at 360 (Harlan, J., concurring) (noting an “electronic as well as [a] physical intrusion into a place” where an individual has a reasonable expectation of privacy “may constitute a violation of the Fourth Amendment” (emphasis added)).
[267] See Katz, 389 U.S. at 361 (Harlan, J., concurring); Winn, supra note 18, at 8.
[268] See Katz, 389 U.S. at 361 (Harlan, J., concurring) (explaining an actual expectation of privacy must “be one that society is prepared to recognize as ‘reasonable’” (emphasis added)); Winn, supra note 18, at 8.
[269] See Generally, Lexico, https://www.lexico.com/en/definition/generally [https://perma.cc/S5UE-48HS] (“In most cases; usually.”).
[270] See, e.g., Katz, 389 U.S. at 361 (Harlan, J., concurring); see also United States v. Jones, 565 U.S. 400, 407 (2012).
[271] “Incorporation” refers to “[t]he process of applying the provisions of the Bill of Rights to the states by interpreting the 14th Amendment’s Due Process Clause as encompassing those provisions.” Incorporation, Black’s Law Dictionary (11th ed. 2019). See generally U.S. Const. amend. XIV, § 1 (“No State shall . . . deprive any person of life, liberty, or property, without due process of law . . . .”).
[272] E.g., Griswold v. Connecticut, 381 U.S. 479, 499–500 (1965) (Harlan, J., concurring); see Dane, supra note 17, at 551–54, 558; Lori G. Wentworth, Justice Harlan, Justice Rehnquist, and the Values of Federalism, 36 N.Y.L. Sch. L. Rev. 255, 261 (1991).
[273] The Fifth Amendment’s Due Process Clause applies only to the federal government, while that of the Fourteenth Amendment applies to the states. Compare U.S. Const. amend. V, with U.S. Const. amend. XIV.
[274] Wentworth, supra note 272, at 262; cf. Friedman, supra note 12, at 156 (“Probable cause itself is an accommodation between society’s need to investigate and the individual’s liberty to be free of government intrusion.”).
[275] Poe v. Ullman, 367 U.S. 497, 541 (1961) (Harlan, J., dissenting) (second alteration in original) (quoting Corfield v. Coryell, 6 F. Cas. 546 (C.C.E.D. Pa. 1823) (No. 3,230)).
[276] Id. at 544 (quoting Irvine v. California, 347 U.S. 128, 147 (1954) (Frankfurter, J., dissenting)).
[277] Griswold, 381 U.S. at 500 (Harlan, J., concurring) (quoting Palko v. Connecticut, 302 U.S. 319, 325 (1937)); Wentworth, supra note 272, at 262.
[278] Katz v. United States, 389 U.S. 347, 361 (1967) (Harlan, J., concurring).
[279] Poe, 367 U.S. at 544 (Harlan, J., dissenting).
[280] Id. at 550 (quoting Olmstead v. United States, 277 U.S. 438, 478 (1928) (Brandeis, J., dissenting)); see also supra note 48 and accompanying text. Interestingly, Justice Harlan was friends with Judge Henry Friendly, who was Justice Brandeis’s law clerk during the term in which Olmstead was decided. See Henry J. Friendly, Mr. Justice Harlan, as Seen by a Friend and Judge of an Inferior Court, 85 Harv. L. Rev. 382, 382 (1971); Michael Norman, Henry J. Friendly, Federal Judge in Court of Appeals, Is Dead at 82, N.Y. Times, Mar. 12, 1986, at B6, https://www.nytimes.com/1986/03/12/obituaries/henry-j-friendly-federal-judge-in-court-of-appeals-is-dead-at-82.html [https://perma.cc/6VUJ-RQKK]. Also notable is that Chief Justice John Roberts, the author of the Carpenter majority, was a law clerk for Judge Friendly and has highlighted Justice Harlan as one of his favorite Justices. See Timothy P. O’Neill, Harlan on My Mind: Chief Justice Roberts and the Affordable Care Act, 3 Calif. L. Rev. Circuit 170, 176, 182–83 (2012). “It should make us curious about what Roberts learned as a young law clerk working for the legendary Henry Friendly.” Id. at 182–83.
[281] Poe, 367 U.S. at 550 (Harlan, J., dissenting) (quoting Boyd v. United States, 116 U.S. 616, 630 (1886)).
[282] Olmstead, 277 U.S. at 478 (Brandeis, J., dissenting).
[283] Katz, 389 U.S. at 362 (Harlan, J., concurring).
[284] United States v. White, 401 U.S. 745, 786–87 (Harlan, J., dissenting); see also id. at 787–90.
[285] See, e.g., Clapper v. Amnesty Int’l USA, 568 U.S. 398 (2013); Laird v. Tatum, 408 U.S. 1 (1972); ACLU v. NSA, 493 F.3d 644, 654 (6th Cir. 2007); Jonathon W. Penney, Chilling Effects: Online Surveillance and Wikipedia Use, 31 Berkeley Tech. L.J. 117 (2016); Kelsey Cora Skaggs, Surveilling Speech and Association: NSA Surveillance Programs and the First Amendment, 18 U. Pa. J. Const. L. 1479 (2016); Katherine J. Strandburg, Membership Lists, Metadata, and Freedom of Association’s Specificity Requirement, 10 I/S: J.L. & Pol’y for Info. Soc’y 327 (2014); Nafeez Ahmed, ‘Chilling Effect’ of Mass Surveillance Is Silencing Dissent Online, Study Says, Vice (Mar. 17, 2016, 6:00 AM), https://www.vice.com/en_us/article/aekedb/chilling-effect-of-mass-surveillance-is-silencing-dissent-online-study-says [https://perma.cc/VUJ6-ZEYF].
[286] See White, 401 U.S. at 784 (Harlan, J., dissenting) (“The controlling principle is ‘to recognize that the Fourth Amendment governs all intrusions by agents of the public upon personal security, and to make the scope of the particular intrusion, in light of all the exigencies of the case, a central element in the analysis of reasonableness.’” (quoting Terry v. Ohio, 392 U.S. 1, 18 n.1 (1968)) (citing Davis v. Mississippi, 394 U.S. 721, 727 (1969))).
[288] See Katz, 389 U.S. at 362 (Harlan, J., concurring).
[289] White, 401 U.S. at 786 (Harlan, J., dissenting).
[290] 159 F.2d 169 (2d Cir. 1947) (Hand, J.).
[292] Notably, Judge Hand was influential in Justice Harlan’s career. See Yarbrough, supra note 260.
[293] See Katz, 389 U.S. at 360–61 (Harlan, J., concurring); Amar, supra note 30, at 774.
[294] See supra text accompanying notes 286–288.
[295] Carpenter v. United States, 138 S. Ct. 2206, 2221–22 (2018).
[296] United States v. White, 401 U.S. 745, 787–88 & nn.23–24 (1971) (Harlan, J., dissenting); see also Olmstead v. United States, 277 U.S. 438, 479 & n.12 (1928) (Brandeis, J., dissenting); In re Application of the U.S. for an Order Authorizing the Release of Historical Cell-Site Info., 736 F. Supp. 2d 578, 595–96 (E.D.N.Y. 2010), rev’d (Nov. 29, 2010); Tonja Jacobi & Jonah Kind, Criminal Innovation and the Warrant Requirement: Reconsidering the Rights-Police Efficiency Trade-Off, 56 Wm. & Mary L. Rev. 759, 785 (2015); Cohen, supra note 48, at 1911.
[297] But cf. Matthew B. Kugler & Lior Jacob Strahilevitz, The Myth of Fourth Amendment Circularity, 84 U. Chi. L. Rev. 1747 (2017) (providing empirical data that Riley did not alter societal expectations of privacy in the long term).
[298] See Cohen, supra note 48, at 1911.
[299] See id. at 1912, 1919–20.
[300] See White, 401 U.S. at 787, 789–90 (Harlan, J., dissenting); Cohen, supra note 48, at 1912, 1919–20; see also Ashcroft v. ACLU, 542 U.S. 656, 670–71 (2004) (explaining the likelihood of prosecution for speech may cause a “serious chill upon protected speech”); Ahmed, supra note 285; Penney, supra note 285, at 169–71; Jonathon W. Penney, Whose Speech is Chilled by Surveillance?, Slate (July 7, 2017, 7:32 AM), https://slate.com/technology/2017/07/women-young-people-experience-the-chilling-effects-of-surveillance-at-higher-rates.html [https://perma.cc/KT4J-EDU4]; Neil M. Richards, The Dangers of Surveillance, 126 Harv. L. Rev. 1934, 1945–52 (2013); Richards, supra note 48, at 97–98; cf. Olmstead, 277 U.S. at 479 n.12 (Brandeis, J., dissenting).
[301] U.S. Const. amend. IV; White, 401 U.S. at 781 n.17, 789–90 (Harlan, J., dissenting).
[302] Carpenter v. United States, 138 S. Ct. 2206, 2221 (2018); see Friedman, supra note 12, at 81–82, 253–54.
[303] Carpenter, 138 S. Ct. at 2253 (Alito, J., dissenting) (quoting Hale v. Henkel, 201 U.S. 43, 73 (1906)).
[304] Id. at 2256; accord Brief for Respondent at 46, Carpenter, 138 S. Ct. 2206 (No. 16-402); see also Friedman, supra note 12, at 237.
[305] See, e.g., Friedman, supra note 12, at 251.
[306] See Jacobi & Kind, supra note 296, at 807–09; cf. White, 401 U.S. at 787; Olmstead v. United States, 277 U.S. 438, 479 n.12 (1928) (Brandeis, J., dissenting).
[307] Smith v. Maryland, 442 U.S. 735, 745 (1979); see also Carpenter, 138 S. Ct. at 2261 (Alito, J., dissenting).
[308] See Bourguignon, supra note 260, at 278.
[310] See supra text accompanying note 125.
[311] See Penney, supra note 285; Dawinder S. Sidhu, The Chilling Effect of Government Surveillance Programs on the Use of the Internet by Muslim-Americans, 7 U. Md. L.J. Race Religion Gender & Class 375 (2007); Skaggs, supra note 285; Strandburg, supra note 285; Ahmed, supra note 285; Paulina Perlin, ACLU v. NSA: How Greater Transparency Can Reduce the Chilling Effects of Mass Surveillance, Yale L. Sch. Media Freedom & Info. Access Clinic: Case Disclosed (Dec. 6, 2017), https://law.yale.edu/mfia/case-disclosed/aclu-v-nsa-how-greater-transparency-can-reduce-chilling-effects-mass-surveillance [https://perma.cc/6N5A-XHEB]; Penney, supra note 300.
[312] See discussion supra Section III.A.
[313] See discussion supra Section I.A.
[314] For example, an order issued under the SCA. See supra text accompanying notes 168–170.
[315] See generally Mapp v. Ohio, 367 U.S. 643 (1961); Silverthorne Lumber Co. v. United States, 251 U.S. 385 (1920); Weeks v. United States, 232 U.S. 383 (1914).
[316] See United States v. White, 401 U.S. 745, 781 n.17 (1971) (Harlan, J., dissenting).