Long before the National Security Agency was caught electronically surveilling Americans without first obtaining a warrant, local law enforcement agencies in about 15 states had been using technology to collect information from nearby cellular devices -- also without obtaining a warrant. Known as a Stingray, the suitcase-sized surveillance tool
Like NSA, Local Police Spy On Americans Without Warrant
Stingrays and other cell surveillance tools have been used in the U.S. for years without the knowledge of the public or even defense attorneys and judges.