The Supreme Court ruled Friday that law enforcement in most cases has to obtain a warrant in order to search and seize long-term cell phone records that would show a person's location.
In a 5-4 ruling, the court held that the Fourth Amendment's protections against an unreasonable search protects people from having the government acquire their cell-site records from wireless providers in run-of-the-mill criminal investigations.
Chief Justice John Roberts sided with the court's four liberal justices, Ruth Bader Ginsburg, Stephen Breyer, Sonia Sotomayor and Elena Kagan, to make up the majority.
Justice Anthony Kennedy dissented along with conservative Justices Clarence Thomas, Samuel Alito and Neil Gorsuch.
The ruling marked a major win for privacy rights in the digital age.
The case before the court centered on Timothy Carpenter, who argued the government violated his Fourth Amendment rights against unreasonable search and seizure when it obtained records from his wireless provider revealing his location over 127 days.
Authorities used the data as evidence at his trial to convict him of a string of robberies at Radio Shack and T-Mobile stores in Michigan and Ohio from December 2010 to March 2011.
The government claimed it was well within its right under the Stored Communications Act of 1986 to obtain the records through a court order, which requires police to show reasonable grounds to believe the information is relevant to their criminal investigation.
For a warrant, police have to show probable cause that the crime occurred.
The Sixth Circuit Court of Appeals ruled against Carpenter, upholding the district court ruling, sentencing Carpenter to 1,395 months in prison.
The court held that no search occurred under the Fourth Amendment because Carpenter had no reasonable expectation of privacy in cell phone location records held by his service provider.
In reversing the lower court ruling, Roberts disagreed. He said Carpenter did have a reasonable expectation of privacy.
“As with GPS information, the time-stamped data provides an intimate window into a person’s life revealing not only his particular movements, but through them his familial, political, professional, religious and sexual associations,” he said. “These location records hold for many Americans the ‘privacies of life.’”
Roberts noted that location data has become so precise that it gives the government a near perfect surveillance. Unlike with GPS tracking, he said police don’t even need to know in advance who they want to follow or when.
“Whoever the suspect turns out to be, he has effectively been tailed every moment of every day for five years, and the police may — in the government’s view — call upon the results of that surveillance without regard to the constraints of the Fourth Amendment,” he said.
"Only a few without cell phones could escape this tireless and absolute surveillance.”
In a footnote in the 23-page ruling, Roberts said the court need not decide whether there is a limited period for which the government can obtain an individual’s historical cell-site location data without a warrant.
For Friday’s opinion, Roberts said it’s sufficient for the court to hold that accessing seven days worth of cell phone location data is enough to require a warrant.
In a dissenting opinion, Kennedy said the court's ruling puts needed, reasonable, accepted, lawful and congressionally authorized criminal investigations at risk in serious cases.
"And it places undue restrictions on the lawful and necessary enforcement powers exercised not only by the federal government, but also by law enforcement in every state and locality throughout the nation."
But Roberts said law enforcement can obtain an exemption from the warrant requirement in urgent situations.
“Lower courts for instance, have approved warrantless searches related to bomb threats, active shootings and child abductions,” he said. “Our decision today does not call into doubt warrantless access to CSLI [cell-site location information] in such circumstances.”
The ACLU, which represented Carpenter in the case, hailed the court for bringing privacy laws in line with modern day life.
“The government can no longer claim that the mere act of using technology eliminates the Fourth Amendment’s protections,” ACLU attorney Nathan Freed Wessler said in a statement.
“Today’s decision rightly recognizes the need to protect the highly sensitive location data from our cell phones, but it also provides a path forward for safeguarding other sensitive digital information in future cases — from our emails, smart home appliances, and technology that is yet to be invented.”