The U.S. Supreme Court today agreed to hear an important digital privacy rights case that will determine if police have to get a warrant to access your cellphone location data, which is archived by wireless carriers.
The top four U.S. wireless carriers — AT&T, Sprint, T-Mobile, and Verizon– get tens of thousands of requests from law enforcement each year for user location data, often referred to as "cell site location information," or CSLI.
The justices agreed to hear an appeal brought by a man who was arrested in 2011 as part of an investigation into a string of armed robberies at Radio Shack and T-Mobile stores in the Detroit area over the preceding months. Police helped establish that the man, Timothy Carpenter, was near the scene of the crimes by securing cell site location information from his cellphone carrier.
At issue is whether failing to obtain a warrant violates a defendant's right to be free from unreasonable searches and seizures under the U.S. Constitution's Fourth Amendment.
The information that law enforcement agencies can obtain from wireless carriers shows which local cellphone towers users connect to at the time they make calls. Police can use historical data to determine if a suspect was in the vicinity of a crime scene or real-time data to track a suspect.
(…) Carpenter's bid to suppress the evidence failed and he was convicted of six robbery counts. On appeal, the Cincinnati, Ohio-based 6th U.S. Circuit Court of Appeals upheld his convictions, finding that no warrant was required for the cellphone information.
Civil liberties lawyers say that police need "probable cause," and therefore a warrant, in order to avoid constitutionally unreasonable searches.
But, based on a provision of a federal law called the Stored Communications Act, the government said it does not need probable cause to obtain customer records. Instead, the government said, prosecutors must show only that there are "reasonable grounds" for the records and that they are "relevant and material" to an investigation.
Carpenter is represented by the ACLU.
"Because cellphone location records can reveal countless private details of our lives, police should only be able to access them by getting a warrant based on probable cause," Nathan Freed Wessler, a staff attorney with the ACLU's Speech, Privacy and Technology Project, told Reuters.