Supreme Court says police need warrant to track cellphones
WASHINGTON — In a victory for privacy in the digital era, the Supreme Court ruled Friday that the Constitution protects tracking data from a cellphone, requiring police to have a search warrant to obtain cell tower records that can show a person’s movement over days or weeks.
The justices, by a 5-4 vote, said the Fourth Amendment protects the tracking data, even though these records are collected and held by a private company, not by the individual who is the target of the search.
Privacy advocates hailed the decision as a landmark that updates the law to keep pace with the way modern technology has vastly expanded the amount of data that can be easily compiled and stored.
This nation of 326 million people has 396 million cellphone accounts, Chief Justice John G. Roberts noted, and each of those phones regularly sends signals that record the movement of its often-unwitting user.
The “seismic shifts in technology” would permit total surveillance of the public, and “we decline to grant the state unrestricted access” to these databases, Roberts said. He was joined by the court’s four liberal justices.
The four dissenters, however, warned the court was venturing into new territory by extending privacy rights to information that is not truly private and was not created or held by the user of the cellphone. They also worried the warrant requirement could hamper investigators who are in search of dangerous criminals.
The ruling likely will require changes in the way the FBI and police departments in much of the country handle investigations. The effect will be less in California, however, since the state Legislature in 2015 adopted a law that requires investigators to have a search warrant before they can seek cellphone records.
Last year, police investigators in Los Angeles Sheriff’s Department said the requirement to get a warrant for tracking data had caused them little trouble.
It is not clear how the ruling will affect other disputes over electronic information. Roberts said the decision in Carpenter vs. United States was a “narrow one” that applied only to cellphone tracking data. The dissenters warned the rule inevitably will expand to shield other types of electronic data — a forecast that many privacy advocates hope will prove accurate.
The ruling reflects the Supreme Court’s increasing concern over the vast amount of private information that can be obtained and stored through digital technology — and often without the knowledge of the user.
“This is a groundbreaking victory for Americans’ privacy rights in the digital age,” said ACLU attorney Nathan Freed Wessler, who argued the case before the court in November.
“The Supreme Court has given privacy law an update that it has badly needed for many years, finally bringing it in line with the realities of modern life. Today’s decision rightly recognizes the need to protect the highly sensitive location data from our cellphones, but it also provides a path forward for safeguarding other sensitive digital information in future cases — from our e-mails, smart home appliances, and technology that is yet to be invented.”
The case involved Timothy Carpenter, the accused leader of an armed robbery gang in the Detroit area, who was convicted after the jury was told that his movements were tracked for 127 days using data from cell towers. The tracking data showed he was near the scene of several of the robberies.
Under a federal law known as the Stored Communications Act, investigators were able to obtain these records from the phone companies by going before a judge and showing they had facts demonstrating the cellphone records were “relevant and material to an ongoing criminal investigation.”