Alex Hern, writing for The Guardian:

Sensitive information about the location and staffing of military bases and spy outposts around the world has been revealed by a fitness tracking company.

The details were released by Strava in a data visualisation map that shows all the activity tracked by users of its app, which allows people to record their exercise and share it with others.

The map, released in November 2017, shows every single activity ever uploaded to Strava – more than 3 trillion individual GPS data points, according to the company. The app can be used on various devices including smartphones and fitness trackers like Fitbit to see popular running routes in major cities, or spot individuals in more remote areas who have unusual exercise patterns.

Another article about this breach: Strava’s fitness tracker heat map reveals the location of military bases – Andrew Liptak, The Verge