Yes. But for you there are sites that do this for a small fee.
You steal a phone? Likely if the phone is stolen even after removing the lock nobody will activate service on it.
FYI ios is still running behind that lock screen. In developer mode you can remove all sorts of ios parts. You can also replace them with fresh ones. Simply removing icloud app and findmyiphone you can re install them with fresh install and no more account attached.
Are you greeted with the lock screen or can you access ios but just locked to an account?
Most sites charge anywhere from 15-25 bucks to remove the lock screen.