“What’s left of the Fourth Amendment? Today we use the Internet to do most everything. Smartphones make it easy to keep a calendar, correspond with friends, make calls, conduct banking, and even watch the game. Countless Internet companies maintain records about us and, increasingly, for us. Even our most private documents—those that, in other eras, we would have locked safely in a desk drawer or destroyed—now reside on third party servers.”
Visiting Professor, Georgetown University Law Center and Senior Fellow at the Brennan Center for Justice
Associate Professor, Sandra Day O'Connor College of Law at Arizona State University
In Carpenter, the Supreme Court once again addressed whether the Fourth Amendment’s prohibition on unreasonable searches and seizures applied to modern technology—in this case, to cellphones and smartphones. Can the government subpoena third-party telecommunications providers to provide your physical location, transmitted on an almost ongoing basis to the company cell sites? Is the Fourth Amendment well suited to the Internet Age, where most of our possessions and documents can be found in “the cloud” and in the possession of third-party technology companies?
As technology has enhanced the Government’s capacity to encroach upon areas normally guarded from inquisitive eyes, this Court has sought to “assure [ ] preservation of that degree of privacy against government that existed when the Fourth Amendment was adopted.” For that reason, we [previously] rejected . . . a “mechanical interpretation” of the Fourth Amendment and held that use of a thermal imager to detect heat radiating from the side of the defendant’s home was a search. Because any other conclusion would leave homeowners “at the mercy of advancing technology,” we determined that the Government—absent a warrant—could not capitalize on such new sense-enhancing technology to explore what was happening within the home. . . .
The question we confront today is how to apply the Fourth Amendment to a new phenomenon: the ability to chronicle a person’s past movements through the record of his cell phone signals. . . . Much like GPS tracking of a vehicle, cell phone location information is detailed, encyclopedic, and effortlessly compiled. . . . [I]n 1979 [when a prior case was decided], few could have imagined a society in which a phone goes wherever its owner goes, conveying to the wireless carrier not just dialed digits, but a detailed and comprehensive record of the person’s movements. . . .
Given the unique nature of cell phone location records, the fact that the information is held by a third party does not by itself overcome the user’s claim to Fourth Amendment protection. Whether the Government employs its own surveillance technology . . . or leverages the technology of a wireless carrier, we hold that an individual maintains a legitimate expectation of privacy in the record of his physical movements as captured through [cell phone site data]. The location information obtained from Carpenter’s wireless carriers was the product of a search. . . .
As with GPS information, the time-stamped data provides an intimate window into a person’s life, revealing not only his particular movements, but through them his “familial, political, professional, religious, and sexual associations.” These location records “hold for many Americans the ‘privacies of life.’” . . . A cell phone faithfully follows its owner beyond public thoroughfares and into private residences, doctor’s offices, political headquarters, and other potentially revealing locales. Accordingly, when the Government tracks the location of a cell phone it achieves near perfect surveillance, as if it had attached an ankle monitor to the phone’s user.
Moreover, the retrospective quality of the data here gives police access to a category of information otherwise unknowable. . . . Unlike with the GPS device . . . police need not even know in advance whether they want to follow a particular individual, or when. Whoever the suspect turns out to be, he has effectively been tailed every moment of every day for five years . . . .
The Government’s acquisition of the cell-site records was a search within the meaning of the Fourth Amendment. . . . [T]he Government must generally obtain a warrant supported by probable cause before acquiring such records. . . .
. . . . The Court has twice held that individuals have no Fourth Amendment interests in business records which are possessed, owned, and controlled by a third party. This is true even when the records contain personal and sensitive information. So when the Government uses a subpoena to obtain, for example, bank records, telephone records, and credit card statements from the businesses that create and keep these records, the Government does not engage in a search of the business’s customers within the meaning of the Fourth Amendment.
In this case petitioner challenges the Government’s right to use compulsory process to obtain a now-common kind of business record: cell-site records held by cell phone service providers. The Government acquired the records through an investigative process enacted by Congress. Upon approval by a neutral magistrate, and based on the Government’s duty to show reasonable necessity, it authorizes the disclosure of records and information that are under the control and ownership of the cell phone service provider, not its customer. . . .
In concluding that the Government engaged in a search, the Court unhinges Fourth Amendment doctrine from the property-based concepts that have long grounded the analytic framework that pertains in these cases. In doing so it draws an unprincipled and unworkable line between cell-site records on the one hand and financial and telephonic records on the other. According to today’s majority opinion, the Government can acquire a record of every credit card purchase and phone call a person makes over months or years without upsetting a legitimate expectation of privacy. But, in the Court’s view, the Government crosses a constitutional line when it obtains a court’s approval to issue a subpoena for more than six days of cell-site records in order to determine whether a person was within several hundred city blocks of a crime scene. That distinction is illogical and will frustrate principled application of the Fourth Amendment in many routine yet vital law enforcement operations. . . .
A person’s movements are not particularly private. . . . Today expectations of privacy in one’s location are, if anything, even less reasonable than . . . 30 years ago. Millions of Americans choose to share their location on a daily basis, whether by using a variety of location-based services on their phones, or by sharing their location with friends and the public at large via social media. . . .
What persons purchase and to whom they talk might disclose how much money they make; the political and religious organizations to which they donate; whether they have visited a psychiatrist, plastic surgeon, abortion clinic, or AIDS treatment center; whether they go to gay bars or straight ones; and who are their closest friends and family members. The troves of intimate information the Government can and does obtain using financial records and telephone records dwarfs what can be gathered from cell-site records. . . .
Technological changes involving cell phones have complex effects on crime and law enforcement. Cell phones make crimes easier to coordinate and conceal, while also providing the Government with new investigative tools that may have the potential to upset traditional privacy expectations. How those competing effects balance against each other, and how property norms and expectations of privacy form around new technology, often will be difficult to determine during periods of rapid technological change. In those instances, and where the governing legal standard is one of reasonableness, it is wise to defer to legislative judgments like the one embodied in § 2703(d) of the Stored Communications Act. . . .
This case should not turn on “whether” a search occurred. It should turn, instead, on whose property was searched. The Fourth Amendment guarantees individuals the right to be secure from unreasonable searches of “their persons, houses, papers, and effects.” . . . By obtaining the cell-site records of MetroPCS and Sprint, the Government did not search Carpenter’s property. He did not create the records, he does not maintain them, he cannot control them, and he cannot destroy them. Neither the terms of his contracts nor any provision of law makes the records his. The records belong to MetroPCS and Sprint. . . .
The . . . fundamental problem with the Court’s opinion . . . is its use of the “reasonable expectation of privacy” test, which was first articulated by Justice Harlan in Katz v. United States, 389 U.S. 347, 360–361 (1967) (concurring opinion). The Katz test has no basis in the text or history of the Fourth Amendment. And, it invites courts to make judgments about policy, not law. Until we confront the problems with this test, Katz will continue to distort Fourth Amendment jurisprudence. . . .
At the founding, “search” did not mean a violation of someone’s reasonable expectation of privacy. The word was probably not a term of art, as it does not appear in legal dictionaries from the era. And its ordinary meaning was the same as it is today: “‘[t]o look over or through for the purpose of finding something; to explore; to examine by inspection; as, to search the house for a book; to search the wood for a thief.’” The word “search” was not associated with “reasonable expectation of privacy” until Justice Harlan coined that phrase in 1967. The phrase “expectation(s) of privacy” does not appear in the pre-Katz federal or state case reporters, the papers of prominent Founders, early congressional documents and debates, collections of early American English texts, or early American newspapers. . . .
Of course, the founding generation understood that, by securing their property, the Fourth Amendment would often protect their privacy as well. But the Fourth Amendment’s attendant protection of privacy does not justify Katz’s elevation of privacy as the sine qua non of the Amendment. . . . In shifting the focus of the Fourth Amendment from property to privacy, the Katz test also reads the words “persons, houses, papers, and effects” out of the text. . . .
. . . . The order in this case was the functional equivalent of a subpoena for documents, and there is no evidence that these writs were regarded as “searches” at the time of the founding. Subpoenas duces tecum and other forms of compulsory document production were well known to the founding generation. Blackstone dated the first writ of subpoena to the reign of King Richard II in the late 14th century . . . .
Talk of kings and common-law writs may seem out of place in a case about cell-site records and the protections afforded by the Fourth Amendment in the modern age. But this history matters, not least because it tells us what was on the minds of those who ratified the Fourth Amendment and how they understood its scope. That history makes it abundantly clear that the Fourth Amendment, as originally understood, did not apply to the compulsory production of documents at all. . . .
General warrants and writs of assistance were noxious not because they allowed the Government to acquire evidence in criminal investigations, but because of the means by which they permitted the Government to acquire that evidence. Then, as today, searches could be quite invasive. . . . Private area after private area becomes exposed to the officers’ eyes as they rummage through the owner’s property in their hunt for the object or objects of the search. If they are searching for documents, officers may additionally have to rifle through many other papers—potentially filled with the most intimate details of a person’s thoughts and life—before they find the specific information they are seeking. Physical destruction always lurks as an underlying possibility . . . .
Compliance with a subpoena duces tecum requires none of that. A subpoena duces tecum permits a subpoenaed individual to conduct the search for the relevant documents himself, without law enforcement officers entering his home or rooting through his papers and effects. As a result, subpoenas avoid the many incidental invasions of privacy that necessarily accompany any actual search. And it was those invasions of privacy—which, although incidental, could often be extremely intrusive and damaging—that led to the adoption of the Fourth Amendment. . . .
Holding that subpoenas must meet the same standard as conventional searches will seriously damage, if not destroy, their utility. Even more so than at the founding, today the Government regularly uses subpoenas duces tecum and other forms of compulsory process to carry out its essential functions. Grand juries, for example, have long “compel[led] the production of evidence” in order to determine “whether there is probable cause to believe a crime has been committed.” Almost by definition, then, grand juries will be unable at first to demonstrate “the probable cause required for a warrant.” If they are required to do so, the effects are as predictable as they are alarming: Many investigations will sputter out at the start, and a host of criminals will be able to evade law enforcement’s reach. . . .
The Fourth Amendment restricts the conduct of the Federal Government and the States; it does not apply to private actors. But today, some of the greatest threats to individual privacy may come from powerful private companies that collect and sometimes misuse vast quantities of data about the lives of ordinary Americans. If today’s decision encourages the public to think that this Court can protect them from this looming threat to their privacy, the decision will mislead as well as disrupt. . . .
In the late 1960s this Court suggested for the first time that a search triggering the Fourth Amendment occurs when the government violates an “expectation of privacy” that “society is prepared to recognize as ‘reasonable.’” Then, in a pair of decisions in the 1970s applying the Katz test, the Court held that a “reasonable expectation of privacy” doesn’t attach to information shared with “third parties.” By these steps, the Court came to conclude, the Constitution does nothing to limit investigators from searching records you’ve entrusted to your bank, accountant, and maybe even your doctor.
What’s left of the Fourth Amendment? Today we use the Internet to do most everything. Smartphones make it easy to keep a calendar, correspond with friends, make calls, conduct banking, and even watch the game. Countless Internet companies maintain records about us and, increasingly, for us. Even our most private documents—those that, in other eras, we would have locked safely in a desk drawer or destroyed—now reside on third party servers. . . .
True to those words and their original understanding, the traditional approach asked if a house, paper or effect was yours under law. . . . [T]he fact that a third party has access to or possession of your papers and effects does not necessarily eliminate your interest in them. Ever hand a private document to a friend to be returned? Toss your keys to a valet at a restaurant? Ask your neighbor to look after your dog while you travel? . . . Entrusting your stuff to others is a bailment. A bailment is the “delivery of personal property by one person (the bailor) to another (the bailee) who holds the property for a certain purpose.” A bailee normally owes a legal duty to keep the item safe, according to the terms of the parties’ contract if they have one, and according to the “implication[s] from their conduct” if they don’t. . . .
Our Fourth Amendment jurisprudence already reflects this truth. In Ex parte Jackson, 96 U.S. 727 (1878), this Court held that sealed letters placed in the mail are “as fully guarded from examination and inspection, except as to their outward form and weight, as if they were retained by the parties forwarding them in their own domiciles.” The reason, drawn from the Fourth Amendment’s text, was that “[t]he constitutional guaranty of the right of the people to be secure in their papers against unreasonable searches and seizures extends to their papers, thus closed against inspection, wherever they may be.” It did not matter that letters were bailed to a third party (the government, no less). The sender enjoyed the same Fourth Amendment protection as he does “when papers are subjected to search in one’s own household.”
These ancient principles may help us address modern data cases too. Just because you entrust your data—in some cases, your modern-day papers and effects—to a third party may not mean you lose any Fourth Amendment interest in its contents. . . . [F]ew doubt that e-mail should be treated much like the traditional mail it has largely supplanted—as a bailment in which the owner retains a vital and protected legal interest. . . .
It seems to me entirely possible a person’s cell-site data could qualify as his papers or effects under existing law. . . .
