Commercial Tracking

Apple: iPhone
Earlier this year, researchers found that the iPhone logged location data of cell towers and wifi hotspots.
Google: Android
Google’s Android caches similar location data as the iPhone, though not as much.
Facebook: Places
The location-based product by default allows others to locate you, and cannot be turned off.
AT&T: FamilyMap
The app caches a family member’s whereabouts, allowing an abusive husband to track his wife.
The location-based social networking website leaked user data on a massive scale.
The manufacturer of automotive navigation systems sold data of its customers’ locations.