Stingray cell-site simulator secrecy (2011–2015)
Police departments across the U.S. used Stingray devices, which impersonate cell towers to capture phone locations and data. The FBI required agencies to sign nondisclosure agreements, keeping the technology secret even from judges and the public. ACLU affiliates filed records requests and lawsuits to uncover basic facts about the devices.
Records disclosures forced several departments to release policies and admit Stingray use. Some states passed laws requiring warrants.
Stingray secrecy became a template for the broader fight over police surveillance transparency, prompting courts and legislatures to demand disclosure of automated tracking tools.
Like ALPR cameras today, Stingrays were a police surveillance technology whose basic parameters were hidden from the public until litigation forced disclosure.