[bradart]

They do this solely for registration purposes. aCar is a perfect example. If you register and type in your purchase key, it will only work on your device. This prevents people from stealing your donation key and using it on their phone and also prevents you from giving your donate key to everyone you know. Games also use this often when you register as a user online. The game will know it is you in the event that you had to re install the app down the line.

It seems like everyone here is assuming that every permission used by an app is to f*ck people over. Chill out.