Here's one of the principal organizers of the riots at Berkeley last weekend. She lies in her teeth repeatedly, and absolutely refuses to acknowledge the rule of law or civilized behavior. Listen to her carefully. This is the voice of an avowed enemy of freedom, liberty, and justice.
Anyone who's this dogmatically and ideologically fixated should be regarded in the same light as a cancer invading someone's body. It needs to be dealt with before it kills that body entirely. That can happen through the law and the courts. In many places, it will. The problem is, in a place like Berkeley (or Washington state, from where this woman hails), that's unlikely, because the authorities in those places are often themselves left-wing progressives.
If the rule of law breaks down to the extent that the authorities will not stop people like this (as is apparently the case in Berkeley), be aware that their violent demonstrations are likely to put at least your health, if not your life, and the health and lives of your loved ones, at risk. Therefore, if you should encounter such a demonstration and are forced to defend yourself, bear in mind who and what you're dealing with. These people know no logic, no reason, and no mercy. I submit that a legal, proportional and appropriate response to that threat will not be out of place. If anyone should question that . . . show them this video clip.