Problem is, gps tracking is an integral part of capturing fitness data. Its unlikely that this is being broadcast off base immediately because the apps can store the information for when they're connected to an external network. So the chances are the personnel are conforming to the rules at the time. Competitions on base may even demand the use of fitness trackers/Strava accounts to assess performance - miles done per tour, tour fastest mile etc. This has more to do with how pervasive personal data collection is. And how that data is used. And how people don't understand that just because someone says its anonymous doesn't actually mean it is.