Great. Videotaping is the way to go. Let the cops handle the troublemakers.
I'm not up on law and such, but it would seem to me that there should be a law against, basically, declaring war, even if it is "civil war", if you are a civilian.
At the very least inciting to riot, terroristic threats, something----
If they think you are appreciative of what they are doing, they will be inspired to do more.