The Air Force is warning its troops not to use location-based services such as FourSquare, Facebook Places and Gowalla because they could, er, give away their location.
In an internal document sent to commanders, it points out that "careless use of these services by airmen can have devastating operations, security and privacy implications."
According to AP, similar warnings may be circulated amongst the Army and Marines next week - the Army is responsible for the majority of the 145,000 troops currently in Afghanistan and Iraq.
Sites such as PleaseRobMe have shown the dangers of promiscuously publishing one's whereabouts by showing just how easy it is for burglars to make use of check-in information. PleaseBombMe would have just as good a ring to it.
The DoD is concerned that dozy staff could check in to particular locations and give away military positions to the enemy. And, yes, this is actually a possibility, as there really are FourSquare check-in points in Iraq and Afghanistan.
Earlier this year, the Pentagon announced that it was loosening its restrictions on social networking, and would now allow soldiers to use services such as Facebook and Twitter - as long as they did so wisely.