US military personnel on active duty have been banned from using devices and applications which utilize GPS.
Global Positioning System (GPS) technology is commonly found in a variety of systems, including car navigation, map software, and fitness trackers.
The technology is not only used to tell you where you are or where you need to go; instead, it is also used to monitor exercise and performance levels in fitness trackers, dietary apps, and more.
However, the US Department of Defense (DoD) believes the technology could also be used to "present enemies with information on military operations."
In a memo posted by Deputy Defense Secretary Patrick Shanahan on Monday, the Pentagon revealed the new rules, which will prevent members of the US military on active duty from using fitness trackers, any applications in mobile devices which use GPS, as well as any "other devices and apps that pinpoint and track the location of individuals."
The Pentagon says that the information stored by GPS-based services can be uploaded to servers which then may be shared with third-parties -- and therein lies the risk.
With this information out of the military's control, the DoD is concerned that such data could be shared and used to pinpoint military activity.
"Effective immediately, Defense Department personnel are prohibited from using geolocation features and functionality on government and nongovernment-issued devices, applications and services while in locations designated as operational areas," said Pentagon spokesman Army Col. Robert Manning III.
Manning added that commanders active in "operational areas" will make the final call on what devices, apps, and services are allowed.
However, with so many apps now utilizing GPS -- and sometimes in subtle ways which may not be immediately apparent to users -- maintaining this new policy will likely be a challenge.
The spokesman added that geolocation technologies "present a significant risk to the Department of Defense personnel on and off duty, and to our military operations globally."
Commanders will need to conduct risk assessments and will need to implement the new policy on the ground.
It is not known, however, whether senior military staff have been given any training to this effect and will be able to understand the risks, and benefits, of particular applications -- especially as the DoD is still researching the implications itself.
However, the new rules may be justified. In January, it was discovered that the "Global Heat Map," published by GPS tracking firm Strava, could be used to map the movements of active soldiers in countries including Iraq and Syria.
"Security is at the heart of this guidance. DoD seeking a balanced way that allows for legitimate official and personal uses of geolocation technology that does not impact security," Manning added.