A Crucial Privacy Win as America Turns 250
The Fourth Amendment protects Americans’ “papers and effects[] against unreasonable searches and seizures.” 250 years later, these safeguards remain as essential as ever. Indeed, it is quite challenging to participate in modern society without storing personal information on personal devices like cell phones or laptops. In doing so, we entrust high sensitive information with the expectation it will be secured. For decades, courts have tackled legal foundations around privacy expectations with incremental progress. However, the Supreme Court improved Americans’ digital privacy rights with last week’s decision in Chatrie v. United States, elevating third party protections over stored sensitive information.
The link between privacy expectations and Fourth Amendment searches is itself relatively new. Until 1967, the Supreme Court required warrants only when law enforcement officials trespassed upon a person’s property or seized his tangible effects. However, in Katz v. United States, the Court ruled that installing a listening device on a public telephone booth required a warrant, establishing modern legal requirements: A warrant is required when “a person [has] exhibited an actual (subjective) expectation of privacy and… the expectation be one that society is prepared to recognize as ‘reasonable.’” By tying the Fourth Amendment to individuals’ reasonable privacy expectations, this standard allowed the Fourth Amendment’s scope to evolve with technology.
Unfortunately, the Court soon limited Katz’s protections substantially, holding that warrants were not required to access information voluntarily disclosed to third parties in United States v. Miller. Miller’s holding, known as the third-party doctrine, remained in force for several decades, even as people increasingly shared information with third parties. The doctrine’s shortcomings were apparent long before the internet. As early as 1979, Justice Thurgood Marshall wrote in one dissent that “Unless a person is prepared to forgo use of what for many has become a personal or professional necessity, he cannot help but accept the risk of surveillance.” Citizens effectively faced the choice of foregoing most modern technologies or consenting to warrantless surveillance.
The internet only intensified these concerns. In her 2012 concurrence in United States v. Jones, Justice Sotomayor cautioned that the law’s traditional approach to privacy breaks down in the digital age, where participation in everyday life requires constant disclosure of personal information. As the natural result of more routine activities now requiring consistent sharing of information with third parties, Americans’ Fourth Amendment protections steadily eroded.
In 2018, 42 years after Miller, the Supreme Court at last updated the third-party doctrine. In Carpenter v. United States, the Court found that collecting cell site location information (CSLI) required a warrant. Carpenter rejected the notion that citizens waive their privacy rights simply by using essential digital services. Modern life requires third party trust with vast amounts of personal information, but that necessity does not eliminate a reasonable expectation of privacy or provide law enforcement unfettered access to that data.
Although this judicial opinion transformed the Supreme Court’s understanding of privacy expectations, it declined to clarify whether the third-party doctrine applied to any other technologies. Last week in Chatrie, the Court expanded Fourth Amendment protection to finally fill that gap. At issue was law enforcement’s use of geofence techniques—technologies that rely on virtual boundaries established around real-world locations to trigger automated actions to locate all mobile devices in a given area and determine user locations. Notably, the Court concluded that “An individual has a reasonable expectation of privacy in records about his cell phone’s location, and police intrude on that constitutionally protected interest when they demand the information.” The Court did not disallow all access to location information, but did require that geofence requests satisfy Katz’s reasonableness test.
Chatrie underscored that Carpenter was not a one-off decision. In recent years, the Supreme Court has recognized that traditional applications of the third-party doctrine are increasingly ill-suited to a world where participation in everyday life requires entrusting vast amounts of personal information to digital services. The doctrine has not disappeared, and courts will continue to grapple with how it applies to emerging technologies. But as the United States marks its 250th anniversary, Fourth Amendment protections are stronger than they have been in decades, reflecting a judiciary that has shown a willingness to adapt constitutional principles to the realities of the digital age.
