On Nov. 29, the Supreme Court will hear oral argument in an important case called Carpenter v. United States. Although the question in the case may feel very modern — whether government agents can obtain the location data generated by cellphones without a warrant — history can tell us a lot about how the court should answer that question.

The Fourth Amendment of the U.S. Constitution guarantees that “the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated.” The amendment arose from the Founders’ concern that the newly constituted federal government would try to expand its powers and undermine rights that were guaranteed to Americans by the common law and their state constitutions. Based on experience, they knew that equipping government officers with unfettered discretion to search and seize would be a formidable means of oppressing “the people.”

Prior to the American Revolution, British subjects in the colonies and in England had lived with threats posed by “general warrants.” Unlike contemporary search warrants — which require probable cause, judicial approval, and limits on the place to be searched and the things to be seized — general warrants gave government agents license to search wherever they pleased, no matter their reasons, with impunity. And because the king’s ministers could issue general warrants on their own authority, these devices also opened the door to unchecked executive power.

This, of course, was a recipe for abuse.



Under the authority of general warrants, the king’s agents used the power to search and seize as a tool of oppression, targeting disfavored religious minorities and political opponents, such as those who published pamphlets criticizing the government. Some even used their powers to settle personal vendettas. In a series of mid-18th-century cases, courts in England put a stop to this madness, holding that general warrants violated basic principles of English law and were therefore unreasonable. These courts stressed that the very existence of general warrants made everyone vulnerable to the threat of unreasonable searches and seizures.

For example, one influential decision condemned general warrants as “totally subversive of the liberty of the subject” because they gave officers “a discretionary power … to search wherever their suspicions may chance to fall.” Another warned that “the secret cabinets and bureaus of every subject in this kingdom will be thrown open” if general warrants were not forbidden.

Across the Atlantic, James Otis, the Boston lawyer who popularized the slogan “taxation without representation is tyranny,” denounced general warrants, which British authorities were increasingly using to find smuggled goods on which taxes had not been paid. In a legendary speech, he derided them as “the worst instrument of arbitrary power,” which placed “the liberty of every man in the hands of every petty officer.” John Adams later called Otis’s speech “the first scene of the first act of opposition to the arbitrary claims of Great Britain. Then and there the child Independence was born.”

The Founders recognized that giving the state arbitrary search power harms “the people” in ways that go beyond the indignity of specific trespasses.

After splitting from Britain, many states adopted constitutions that guarded against oppressive searches and seizures, and the Fourth Amendment was later modeled on those protections. Read in this historical context, the Fourth Amendment is aimed at denying executive agents the unfettered discretion to conduct searches because of the pervasive insecurity that such discretion creates and the abuses of power it enables.

This history lesson is significant because it lights the way in the Carpenter case, where the Supreme Court will be considering the Fourth Amendment’s application to “cell site location information.” This is data generated and stored by our cellular service providers as our phones communicate with the providers’ networks of cell towers. It shows where we are most of the time, recording our locations and movements going back months and even years.

According to the federal government, nothing in the Constitution prevents its agents from exploiting cell site location information as they see fit and tracking the whereabouts of anyone or everyone. This is disconcerting. In a friend-of-the-court brief filed with other scholars, we argue that it is also contrary to the text and original meaning of the Fourth Amendment.

This may sound odd since there were no cellphones in 1791 when the Fourth Amendment was ratified. In that pre-digital world, searches usually involved physical intrusions, like seizing papers from a home. Today, law enforcement can track where you have been simply by getting location records from your cellular provider. But the word “search,” then as now, was not limited to trespassing on private property. It meant to “examine,” “look through,” or “try to find,” which clearly includes examining location records to find a person.

And the Founders recognized that giving the state arbitrary search power harms “the people” in ways that go beyond the indignity of specific trespasses. As the Supreme Court explained in its first major decision interpreting the Fourth Amendment, “It is not the breaking of his doors, and the rummaging of his drawers, that constitutes the essence of the offense,” but rather “the invasion of his indefeasible right of personal security” and the state’s unjustified encroachment into the “privacies of life.”

The same dangers of unfettered government power arise when officers can freely track people’s movements by looking through cell site location records. As the court noted recently in Riley v. California, cellphones are essential to modern life. Most of us carry one with us all the time, generating a continuous digital trail of our whereabouts that can reveal intimate relationships, medical conditions, religious practices, political activities, and more. Allowing the government unfettered access to that information would be tantamount to licensing the 24-hour surveillance of everyone. The possibility of such broad and indiscriminate tracking clearly jeopardizes the security of the people against unreasonable searches and seizures. Undoubtedly, therefore, government access to cell site location information must be regulated by the Fourth Amendment.

Significantly, cellphones are only the tip of the iceberg. A new generation of “smart” consumer products, along with the spread of ever-cheaper surveillance technologies, now enables increasingly broad and invasive searches. At stake in Carpenter is the government’s capacity to freely exploit these new technologies to monitor and control “the people” in ways that Justice Sonia Sotomayor has described as “inimical to democratic society.”

This looming dystopia is not inevitable. The Fourth Amendment guarantees protection against precisely such threats. As “the people,” that security is our birthright.