While many of these locations are well known, they may give away info that governments might not want public, such as the likely location of living quarters and the most frequently-trafficked paths. In Afghanistan, the activity data extends beyond bases and hint at patrol or supply routes.

Strava has reminded users that they could turn off location sharing, and that the map doesn't include private activities or areas deemed private. Many people aren't aware of what the app shares, however, and might not understand the implications of publicly sharing that data from sensitive locations. And of course, not every fitness-minded app has a public activity map that makes searches easy. It's doubtful that Strava could have considered every possible effect in advance, but this is a reminder that open data can sometimes include more than some would be comfortable with. Likewise, this might prompt militaries to limit smartphone use or educate soldiers on the importance of privacy.