The Global Positioning System, commonly referred to as GPS, is a space-based satellite navigation system. It’s what allows you to get turn-by-turn directions to the mini-mart in your automobile. But most people don’t know that it also has countless other crucial applications. Among others, it’s the backbone of the global air traffic system. It is also used to control the power grid, to power banking operations (for instance, ATMs depend on it) and to keep oil platforms in position. And virtually all communications systems, like the world’s cellular networks, rely on it.
More:
http://www.wired.com/dangerroom/2012/07/drone-hijacking/all/
