Judge says warrant required for cell phone location data
Aug 23, 2011 // ArsTechnica

A federal district court in New York ruled that the federal government violated the constitution when it obtained without a warrant 113 days of stored data showing the location of a suspect's cell phone. Ars technica reports that the court said:

"'The fiction that the vast majority of the American population consents to warrantless government access to the records of a significant share of their movements by 'choosing' to carry a cell phone must be rejected,' he wrote. ‘In light of drastic developments in technology, the Fourth Amendment doctrine must evolve to preserve cell-phone user's reasonable expectation of privacy in cumulative cell-site-location records.'"