WASHINGTON — The Supreme Court seemed wary Tuesday of allowing police unbridled freedom to search through cellphones of people they arrest, taking on a new issue of privacy in the face of rapidly changing technology.
The justices appeared ready to reject the Obama administration's argument that police should be able to make such searches without first getting warrants.
A key question in two cases argued Tuesday is whether Americans' cellphones, with vast quantities of sensitive records, photos and communications, are a private realm much like their homes.
"People carry their entire lives on their cellphones," Justice Elena Kagan said.
The issue involving devices now carried by almost everyone is the latest in which the court is being asked to adapt old legal rules to 21st-century technological advances.
The court heard arguments in cases involving a drug dealer and a gang member whose convictions turned in part on evidence found on their cellphones.
The justices suggested they might favor limiting warrantless cellphone searches to looking for evidence of the crime on which an arrest is based. Both defendants could lose in such an outcome.
More broadly, however, a decision imposing restrictions on the searches could avoid subjecting people arrested for minor crimes to having all the contents of their cellphones open to police inspection. And it might also prevent the police from using the phones to connect to the Internet and any information stored online.
If police were to arrest someone for driving without a seat belt, Justice Antonin Scalia said, "it seems absurd that they should be able to search that person's iPhone."
The Supreme Court has previously ruled that police can empty a suspect's pockets and examine whatever they find to ensure officers' safety and prevent the destruction of evidence. The Obama administration said cellphones should have no greater protection from a search than anything else police find.
But the defendants in these cases, backed by an array of civil libertarians, librarians and news media groups, argued that cellphones, especially smartphones, are increasingly powerful computers that can store troves of sensitive personal information.