Vice has a long article about how the US military buys commercial location data worldwide.
The U.S. military is buying the granular movement data of people around the world, harvested from innocuous-seeming apps, Motherboard has learned. The most popular app among a group Motherboard analyzed connected to this sort of data sale is a Muslim prayer and Quran app that has more than 98 million downloads worldwide. Others include a Muslim dating app, a popular Craigslist app, an app for following storms, and a “level” app that can be used to help, for example, install shelves in a bedroom.
This isn’t new, this isn’t just data of non-US citizens, and this isn’t the US military. We have lots of instances where the government buys data that it cannot legally collect itself.
Read more: schneier.com