Slate report a good place to start:
https://slate.com/technology/2020/06...d-protest.html
Based on the Slate piece: The cops aren't there because the Mayor ordered them out, abandoning the besieged precinct building. Pissed-off the cops surely. Now it's run by 'volunteer consensus.' Residents and anyone can come and go--unless you are recognized as a not-liked person, then a crowd will form that will--I don't know, yell at you a lot? There are people watching the 'barricades,' but so far, no arms visible and no fighting.
Volunteers are distributing food, and otherwise inventing progressive community stuff. There don't seem to be big problems yet, but I wonder what happens if bad actors come to create violence, set fires, etc. That would sort of be the big test of the no-violence no-police approach.
Historically, the government tolerates stuff like this only so long, then they send in police or troops and 'restore order.' It will be interesting to see how this goes. Pretty progressive mayor may resist the pressure to do something like that. But the more radical of the occupiers will want to make a real revolution out of it, and may force his hand.