The Central Intelligence Agency played a crucial role in helping the Justice Department develop technology that scans data from thousands of U.S. cellphones at a time, part of a secret high-tech alliance between the spy agency and domestic law enforcement, according to people familiar with the work.
The CIA and the U.S. Marshals Service, an agency of the Justice Department, developed technology to locate specific cellphones in the U.S. through an airborne device that mimics a cellphone tower, these people said.
Today, the Justice Department program, whose existence was reported by The Wall Street Journal last year, is used to hunt criminal suspects. The same technology is used to track terror suspects and intelligence targets overseas, the people said.
The program operates specially equipped planes that fly from five U.S. cities, with a flying range covering most of the U.S. population. Planes are equipped with devices—some past versions were dubbed “dirtboxes” by law-enforcement officials—that trick cellphones into reporting their unique registration information.