U.S. military officials have disabled advertising trackers on a range of government-issued phones and computers following reports that commercially available location data was used to target American personnel in the Middle East.

The measures were disclosed in letters released Friday by U.S. Senator Ron Wyden, along with statements provided to Reuters. The move comes after concerns that location information collected through commercial advertising systems could potentially expose the whereabouts of U.S. military personnel.

The U.S. Air Force told Wyden that it had disabled advertising identifiers on computers and mobile devices approximately two months ago. In a separate letter, U.S. Special Operations Command said it had “recently” taken similar steps on its Windows devices.

The Army also confirmed that advertising IDs associated with mobile devices have been disabled since earlier this year.

The decision reflects growing concern within the U.S. military over the security risks posed by commercially collected location data, particularly in regions where American forces may be vulnerable to surveillance or targeting.