Justices uneasy about using cell data against suspects

WASHINGTON — At a lively Supreme Court argument Wednesday, a majority of the justices seemed troubled by the government’s ability to acquire troves of digital data without a warrant.

“Most Americans, I still think, want to avoid Big Brother,” said Justice Sonia Sotomayor. “They want to avoid the concept that government will be able to see and locate you anywhere you are, at any point in time.”

At least five justices seemed prepared to limit the government’s power to obtain records from cellphone companies showing their customers’ locations over long periods of time. But there was no consensus about a rationale for a decision or about how far the court was prepared to go to reshape long-standing constitutional doctrines that allow the government to obtain business records held by third parties.

The case concerns Timothy Ivory Carpenter, who was convicted in robberies of Radio Shack and T-Mobile stores in Michigan and Ohio, based in part on records provided by his cellular carrier showing his movements over several months. Nathan Freed Wessler, a lawyer for Carpenter, said prosecutors had violated the Fourth Amendment, which bars unreasonable searches, by failing to get a warrant. Carpenter is serving a 116-year sentence.

A ruling in Carpenter’s favor could revise a fundamental Fourth Amendment principle: that people have no reasonable expectation of privacy when they voluntarily turn over information to a third party, like a phone company.

“This new technology is raising very serious privacy concerns,” Justice Samuel Alito told Wessler, “but I need to know how much of existing precedent you want us to overrule or declare obsolete.”

The court’s decision will apply the Fourth Amendment, drafted in the 18th century, to a world in which people’s movements are continually recorded by devices in their pockets and cars, by toll plazas and by transit systems.