US military units are putting ID tags in their weapons so they can scan and catalog them faster, but the technology leaves troops vulnerable to attacks because enemy forces could potentially scan them from half a football field away.

The technology is in at least five Air Force bases and in some Army bases, even though the Department of Defense itself calls it a 'significant' security risk. It's not known how many military units are using the technology.

A DoD spokesman says it allows branches to explore their own innovative solutions. 

The Marines have rejected radio frequency identification (RFID) technology in weapons out of security concerns. The Navy said this week that it was halting its own dalliance. 

RFID tags are infused in daily civilian life. They help drivers zip through toll booths and supermarket staff track their merchandise. The tags are also used in passports and amusement park wristbands.

A top weapons expert from the Marines said he saw how they can be read from afar during training exercises in the Southern California desert in December 2018.

'RFID tags on tanks, weapons, magazines, you can ping them and find the disposition of where units are,' said Wesley Turner, who was a Marine chief warrant officer 5 when he spoke to the Associated Press in a spring interview. 'If I can ping it, I can find it and I can shoot you.'