THEY'RE some of the most secretive and clandestine places in the world but they could be threatened by something as simple as fitness tracking apps like Fitbit.
Strava, a social network for runners and cyclists to track their workouts via satellite navigation, released a heat map past year showing the activity of its users worldwide.
Swaths of the United States and Europe show up as a blaze of colour, indicating the millions of users.
Prompted by the observations of 20-year-old Australian student Nathan Ruser, experts weighing in on Twitter have spotted what look to be US and allied bases in Syria, French outposts in Niger, and Turkish troops on patrol in Syria. Security experts say this suggests they "either don't use fitness trackers or prudently turn them off". Who knew that a fitness tracker app would be the one to reveal the locations of secret facilities? But this morning the map appears to have been taken offline.
"Patrol routes, isolated patrol bases, lots of stuff that could be turned into actionable intelligence".
While the location of military bases can be gleaned from local knowledge and satellite imaging tools, the "hotspots" presents a potential security problem of its own - the movement and routine of troops.
Speaking to the ABC, Mr Ruser recalled what he first thought when he looked closely at the images. "I shouldn't be able to establish any Pattern of life info from this far away", Ruser tweeted.
A closer look at those areas brings into focus the locations and outlines of well-known US military bases, as well as other lesser-known and potentially sensitive sites - possibly because American soldiers and other personnel are using fitness trackers as they move around.
Pine Gap's location 20km from Alice Springs was chosen so it would be out of the range of spy ships lurking in global waters off the coast of Australia.
This map of Australia shows all the Strava activity uploaded during the time period.
Multiple news outlets reported that the map, which was posted online late past year, received widespread attention after a Twitter user pointed out it could contain potentially sensitive information.
A spokesman for US Central Command, told The Washington Post the American military was looking into the implications of the map.