I don't see why they would turn violent unless it would be to someone's benefit if they do. Seems it's usually the cops who cause a situation to turn violent and from what I've seen so far, the cops are keeping a distance. So far - so good.
Yep, nothing like having Law Enforcement types around a huge throng of Law Breakers to cause problems.
Give me a break - rioters cause riots, not the other way around - that's like agreeing with folks that it's our fault that 9-11 happened.