Only dirt bags get beaten up by Cops. I have never even been arrested by a Cop because I follow the law. Pretty sure most cops don't just beat up random people they arrest, though my Dad was telling me about this time that five of his guys tried to take down this guy amped up on PcP and they beat him up in trying to take him down.
I once got assaulted by a cop because he thought I was hitting on his girlfriend. In the process my specs got broken too. It almost became a civil case but we managed to settle it out of court.