If you're the owner of an AT&T-branded Nexus 6, and don't want to be, you're in luck. With root, a plastic fork, and a little bit of time, you can remove all of the assorted goodies that the carrier has added and make your Nexus 6 exactly like everyone else's.
Rear Logo Removal
YouTube user Craig Phillips has put up a video showing that the logo on the back of the phone can be easily removed using some kind of sharp object.
[Root Required] How To De-AT&T Your Nexus 6, Make It Look And Function Like Every Other US Variant was written by the awesome team at Android Police.