“This is a groundbreaking victory for Americans' privacy rights in the digital age,” American Civil Liberties Union (ACLU) Attorney Nathan Freed Wessler, who argued the Carpenter v. U.S. case before the court in November, said in a statement.
“Although the ‘ultimate measure of the constitutionality of a governmental search is ‘reasonableness,'' our cases establish that warrantless searches are typically unreasonable where ‘a search is undertaken by law enforcement officials to discover evidence of criminal wrongdoing,'” the court wrote. “Having found that the acquisition of Carpenter's CSLI [cell phone location information] was a search, we also conclude that the Government must generally obtain a warrant supported by probable cause before acquiring such records.
Noting that cell phones and the services they offer are “such a pervasive and insistent part of daily life” as determined in Riley v. the U.S. “that carrying one is indispensable to participation in modern society” and that cell phone logs are created “without any affirmative act on the part of the user beyond powering up,” the Court said “no way to avoid leaving a digital trail of location data” so “in no meaningful sense does the user voluntarily ‘assume the risk' of turning over a comprehensive dossier of his physical movements.”
Saying "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," Wessler explained that "the government can no longer claim that the mere act of using technology eliminates the Fourth Amendment's protections."
But the decision didn't abolish the Third Party Records Doctrine. It "survives; the Court just found that it does not apply to long-term ‘encyclopedic' geographic information generated by cell phones,” said William Snyder, teaching professor at the Syracuse University College of Law. “Striking down the Third Party Records Doctrine would have had enormous implications for government investigations, both for law enforcement and intelligence agencies.”
While the ruling "rightly recognizes the need to protect the highly sensitive location data from our cell phones," Wessler said, "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.”
Greg Nojeim, director of Center for Democracy & Technology's Freedom, Security & Technology Project, concurred, saying in a statement that “the Court's reasoning in this case will be applied to other collections of data, making the Fourth Amendment much more relevant to our digital lives."
Before the decision "content was the only communications information that required a warrant under the Fourth Amendment when held by a third party," said Nojeim.
The ruling is "sufficiently targeted and narrow" enough, according to Information Technology and Innovation Foundation (ITIF) Vice President Daniel Castro, to "uphold consumer's legitimate expectations of privacy," but "avoid having negative repercussions on emerging technologies."
While the justices took a "step toward extending Constitutional protections in the Cyber Age," it is "only a step, said Snyder, who also works with the Institute for National Security and Counterterrorism (INSCT) at Syracuse University. "It points a direction, but the Court is proceeding one step at a time.”