Yep, it looks brutal but this is a snapshot - we've no idea what the guy did.
Here's what I do know: I've had run-ins with the police before, always treated them with respect and always received respect in return. I've not been beaten or even had a hand lifted against me. Why? I don't drink....and 99% of these assholes are pissed out of their tiny minds, and then try to take on the entire police force singlehandedly. When they get tazer'd and beaten shitless I'm behind the police. If these morons don't learn their lessons I'm happy for the cops to beat some respect into them.
Unfortunately alcohol turns most people into belligerent, aggressive, no-respect assholes and is fully legal, whereas marijuana doesn't cause any of these problems and is illegal.