“This is the worst thing about these data trades that happen constantly around the world - each small part of it is (or seems) legit. It’s the bigger picture that makes them look ugly.”
A simple iPhone game leaked location to ad networks with Ask App Not to Track switched on. The bids included screen brightness and whether headphones were plugged in. A broker sells data on about 1.5 billion devices for $120,000 a year. Every step is legal, and the result is surveillance.