"In response to recent letters from Congressman Ed Markey (D-MA), nine mobile wireless carriers have provided detailed reports of law enforcement requests for user cell phone records. These requests come from agencies - across all levels of government - seeking text messages, caller locations, and other information in the course of investigations. The reports show that companies turn over thousands of records a day in response to subpoenas, court orders, police emergencies, and other requests. The volume of requests has increased as much as 16 percent for some companies over the last five years, and some carriers have rejected as many as 15 percent of all requests that they found legally questionable or unjustified. EPIC recently filed amicus briefs in the Fifth Circuit and New Jersey Supreme Court arguing that disclosure of historical and real-time cell phone location information violates a reasonable expectation of privacy and thus requires a warrant under the Fourth Amendment. For more information, see EPIC: In re Historic Cell-Site Location Information, EPIC: State v. Earls."