The Associated Press has found that a technology some units in the U.S. military are using to keep track of guns could let enemies detect troops on the battlefield. The rollout continues — even though the Pentagon itself called use of the tech in firearms a “significant” security risk.

Radio frequency identification technology — RFID, as it is known — is everywhere in daily civilian life. When embedded in military guns, RFID tags can trim hours off time-intensive tasks, such as weapon counts and distribution. But outside armories, the same silent, invisible signals that help automate inventory checks could become an unwanted tracking beacon.