WASHINGTON — The Supreme Court agreed on Monday to decide whether the government needs a warrant to obtain information from cellphone companies showing their customers’ locations.
The new case, Carpenter v. United States, No. 16-402, concerns historical data held by cellphone companies that shows users’ movements over time and could, for instance, place them at the scene of a crime.
In 1979, in Smith v. Maryland, the Supreme Court ruled that a robbery suspect had no reasonable expectation that his right to privacy extended to the numbers dialed from his phone. The court reasoned that the suspect had voluntarily turned over that information to a third party: the phone company.
Relying on the Smith decision’s “third-party doctrine,” federal appeals courts have said that government investigators seeking data from cellphone companies showing users’ movements do not require a warrant.
A federal law, the Stored Communications Act, does require prosecutors to go to court to obtain tracking data, but the showing they must make under the law is not probable cause, the standard for a warrant. Instead, they must demonstrate only that there were “specific and articulable facts showing that there are reasonable grounds to believe” that the records sought “are relevant and material to an ongoing criminal investigation.”