https://www.techdirt.com/articles/20211107/10412047891/seven-years-after-discovering-rogue-stingray-devices-dc-federal-govt-still-doesnt-have-any-idea-what-to-do-about-it.shtml

Seven years ago, wardriving security researchers discovered rogue cell tower simulators being operated near sensitive locations in Washington, DC, presumably by foreign governments.

The company used their ultrasecure CryptoPhone 500 to search for the interceptors, which can compromise phones through baseband hardware and are believed to have a range of roughly 1 mile. ESD America‘s phones allegedly detected telltale signs of call interception in the vicinity of the White House, the Russian Embassy, the Supreme Court, the Department of Commerce, and the Russell Senate Office Building, among other landmark buildings.