Carpenter and Everything After: The Supreme Court Nudges the Fourth Amendment into the Information Age

*This article was first published by the American Bar Association Infrastructure and Regulated Industries in Summer 2019.

Every year, as the calendar turns to June, the legal community looks to the Supreme Court. Eager to get to the Term’s end, the Justices rush to complete all of the outstanding opinions. Since the most difficult and important cases usually take the longest to work out, they are typically the stragglers. June is thus the time when the “blockbuster” opinions are issued—the cases that law professors analyze in their tenure pieces and that law school students study, quite possibly for years to come.

In June 2018, consistent with this history, the legal community awaited the Court’s decision in Carpenter v. United States, a case that considered whether the Fourth Amendment protects an individual’s historical cell-site locational information (“CSLI”) even if the information is in the possession of a cellular service provider. Heading into Carpenter, the so-called “third-party doctrine,” established by the Court over 40 years ago, was understood to stand for the principle that the Fourth Amendment generally did not protect information, such as phone or banking records, voluntarily provided to others. Yet digitization and technological advances had increasingly placed the doctrine under pressure, as an increasing amount of potentially revealing information is now in the hands of third parties. Scholars, advocates, and commentators thus wondered what the Court would do in its direct encounter with what is likely one of the foundational Fourth Amendment issues of our time: Would it hold that the Amendment offers no protection to the digital tracks that are a necessary byproduct of the Information Age? Or would it reverse a doctrine that law enforcement officials have relied on for two generations?

In fact, the Court appeared to do neither.