A fitness app released data showing the location of some secret American military bases because some military personnel used the app while running and record their GPS locations.

The Guardian reported Sunday Strava released its data in November 2017, and now the public has been able to track the runs of military personnel on military bases that are supposed to be secret.

“US Bases are clearly identifiable and mappable.” said Nathan Ruser, an analyst with the Institute for United Conflict Analysts, to The Guardian.

“If soldiers use the app like normal people do, by turning it on tracking when they go to do exercise, it could be especially dangerous.”

Bases in Afghanistan, Djibouti, Syria and domestically are all visible on the map.

Strava tracks the location of people using Fitbits and other fitness devices that can track where a user goes while on a run, walk, bike ride, etc.