Videos have proven to be the best weapon against police brutality there are. Fighting back against a cop is not a good idea. Even a weak cop can use the law against you. Look at the mentally ill man from Fullerton who was literally beaten to death by cops and a jury found them not guilty.

As for race as a factor, abuse by the police can happen to anyone of any color, but it is clearly proportionately higher for blacks than other races or ethnicity. It is also least likely to happen to Asians, more likely for a poor person than a rich one, and more likely for males than females.

It's also true that, relatively speaking, incidents like these are comparatively rare. Most cops don't go around beating up and abusing people. Ideally there shouldn't be any, but no job can only hire perfect people. People are flawed, and even good and decent people can lose their tempers on bad days. So the best thing to do is to be polite, maintain one's cool, know your rights, and keep a friend with a camera nearby.