In a landmark 5-4 decision, the United States Supreme Court held that the government conducts a search under the Fourth Amendment and therefore, absent exigent circumstances, needs a warrant supported by probable cause when obtaining cell-site location information (i.e., records of the cell towers to which mobile devices connect). The majority reached that conclusion based on the determination that such location records are subject to a reasonable expectation of privacy that continues to apply even though the location records are disclosed to the cell phone user’s wireless carrier, a third party.