The Supreme Court agreed on Monday to hear a case examining whether law enforcement can seize and search a cellphone user’s records to reveal that person’s locations and movements.

The case of Carpenter v. United States hinges on the government’s acquisition of location data in 2011 on Timothy Carpenter, a suspect in a criminal investigation in Detroit, without a warrant. Carpenter appealed to the 6th Circuit Court of Appeals, which decided that no warrant is required to seize such materials under the Fourth Amendment of the Constitution.