Justices Appear Divided on Cellphone Warrants

The Supreme Court seemed torn as it considered a pair of cases about whether the police need warrants to search the cellphones of people they arrest.

Some Justices seemed inclined to apply precedents strictly limiting the privacy rights of people under arrest. Those decisions say warrantless searches in connection with arrests are justified by the need to find weapons and to prevent the destruction of evidence.

“Our rule has been that if you carry it on your person, you ought to know it is subject to seizure and examination,” Justice Antonin Scalia said. Other Justices said the vast amounts of data held on smartphones may require a different approach under the Fourth Amendment, which bars unreasonable searches.

“We’re living in a new world,” Justice Anthony M. Kennedy said. “Someone arrested for a minor crime has their whole life exposed on this little device.”

“Most people now do carry their lives on cellphones,” Justice Elena Kagan said, “and that will only grow every single year as young people take over the world.”

Justice Sonia Sotomayor added that the court’s decisions would almost certainly apply to tablet computers and laptops seized at the time of arrest.

But Chief Justice John G. Roberts Jr. said phones also contained “information that is specifically designed to be made public,” mentioning Facebook and Twitter.

The pace of change, Justice Samuel A. Alito Jr. said, made the justices’ jobs very difficult.