Today, the Supreme Court held in Chatrie v. United States that the government conducted a Fourth Amendment search when it used a geofence warrant to obtain user Location History from Google. The majority extended Carpenter v. United States, holding that people have a reasonable expectation of privacy in their cell phones’ location records. The Court did not decide whether the specific warrant here was valid, leaving that question for the Fourth Circuit on remand.

Cato filed an amicus brief, drafted by Laura Bondank-Harmon, the manager of legal programs for the Cato Institute’s Project on Criminal Justice, under the supervision of Matthew Cavedon, the director of the Cato Institute’s Project on Criminal Justice, urging the Court to ground its Fourth Amendment analysis in the constitutional text rather than the malleable reasonable-expectation-of-privacy test. In his concurring opinion, Justice Gorsuch agreed. Citing Cato’s brief, Gorsuch argued that Chatrie’s Location History is his personal property and that a search occurred under the plain meaning of the Fourth Amendment.

While the validity of the geofence warrant itself awaits resolution on remand, today’s decision makes clear that Fourth Amendment protections do not evaporate at the frontier of new technology.

To speak with Matthew Cavedon or Laura Bondank-Harmon about Cato’s amicus brief or about today’s decision, contact Christopher Tarvardian.