They usse carrier whitelists , Which is even worse.

I cannot activded a EU acquired Pixel for instance. Verizon no longer needs to carrier unlock phones after 60 days too :}

Theres multiple carrier that will auto disable you sim if you move it and charge you a fee for it too !

https://www.howardforums.com/threads/is-metro-charging-to-sw...

https://www.reddit.com/r/MetroPCS/comments/1maa4rt/how_much_...

All of this was such a mind fuck.

Land of the free