Departing from prior precedent, the U.S. Supreme Court decided Friday that in order for law enforcement to collect a substantial amount of information from a cell phone provider about one of its subscriber’s whereabouts by using cell phone tower location information, the government must first apply for a search warrant.
 
In Carpenter v. United States, No. 16-402, Chief Justice John Roberts, writing for the majority of the Court, wrote, “We decline to grant the state unrestricted access to a wireless carrier’s database of physical location information.” The Court’s opinion could affect whether and how law enforcement seeks or obtains various types of personal information held by third parties, including email and text messages, internet searches, and bank and credit card records.
 
Carpenter’s attorneys were joined in arguing for privacy protections to apply to cell phone tower records by attorneys for major tech companies such as Apple and Google, who also urged the Court to modernize its Fourth Amendment jurisprudence by shielding cell tower location data, which continuously tracks and pinpoints users’ locations with increasing accuracy, from law enforcement demanding that information without first obtaining a warrant from the court.
 
As noted both by justices who joined in the Chief Justice’s majority opinion and by those who dissented from it, Friday’s decision will have real implications for law enforcement officials and consumers’ privacy in the digital age.