Details are sketchy. Here's what Mrs. Grieve saw (a little before 9). She was traveling solo at the time:
Cop cars racing down Avenue A. People hovering. Some kind of disturbance. Cops seemed over-anxious. A skinny kid picked up a chair and threatened to throw it. The cops said to put it down. He threw it anyway. Cops went ballistic. Chased after him. A crowd followed. A few minutes after, a sit down occured in front of a cop car. Lots of people gathered around in support and just watching. Cops stood emotionless as the crowd called for them to quit, commit suicide . . . and called them Nazis.
To be continued.
[Update: Bob Arihood has more details and photos at Neither More Nor Less. In short, he reports on his site: After the Donut Social, several protestors, including Leftover Crack singer Scott Sturgeon, traveled to Tompkins Square Park "to continue the music with a more intimate acoustic version of the donut concert. For some reason -- we did hear that the arrest may have had something to do with Sturgeon having hurled donuts at the cops earlier at the Donut Social -- police broke-up the gathering and arrested Sturgeon at 8:45 pm . Members of the gathering attempted to prevent the police cruiser carrying Sturgeon from leaving the park. The mini-riot that ensued resulted in 3 more individuals being arrested." ]