High court frets over erosion of privacy

WASHINGTON — Worried about the erosion of privacy amid technological advances, the Supreme Court signaled Wednesday it might restrain the government’s ability to track Americans’ movements through collection of their cellphone information.

The justices heard a case in which the government obtained 127 days of cellphone tower information, without a search warrant, that allowed it to place a criminal suspect in the vicinity of robberies. But underlying the 80-minute argument was unease about how easy it has become to track so many aspects of American lives — and the expectation that new advances would only make things easier.

“Most Americans, I think, still want to avoid Big Brother,” Justice Sonia Sotomayor said, adding that Americans take their phones with them to dressing rooms, bathrooms and bed.

Chief Justice John Roberts, reprising a line from an earlier opinion, noted that having a cellphone these days is a matter of necessity, not choice.

With those devices, Justice Elena Kagan said, authorities have the ability to do “24/7 tracking.”

And the accuracy of cell tower location information also has improved from a vicinity of 10 football fields to half the size of the courtroom in which the argument was occurring, she said.

Those justices appeared to be among a majority of the court that could extend the Constitution’s Fourth Amendment protection against unreasonable searches to apply to police collection of cellphone tower information that has become an important tool in criminal investigations.