I've been watching the livestream and reading
http://twitter.com/#!/Asher_Wolf and as best I can piece it together, this is what happened:
There was a RIP Troy Davis rally in Union Square this evening. When that ended, several hundred people decided to march a couple of miles down Broadway to the park where the OccupyWallStreet gang is hanging out. Once they arrived, there was a more-or-less joint march over to Wall Street, with the two groups combining, then splitting apart, then joining again.
The cops flanked them closely all the way and finally herded them back to the park again. At that point, tempers were running high, so a candlelight vigil was declared to get everyone calmed down again.
Somewhere along the way, 6 or 8 people from the RIP Troy Davis group had been arrested, so a contingent went over to the police precinct to chant in solidarity below the windows. And the last I caught the livefeed, which was just after 11 pm, members of the Malcolm X Grassroots Movement were inviting the OccupyWallStreet people to stand in solidarity with them when their people are arraigned at the Center Street courthouse at around noon tomorrow.
Frankly, I'd like nothing better than to see the unemployed white college graduates and the serious black radicals make common cause. One of the saddest things in the 1960s was when the black-white partnership of the civil rights days fell apart, and though it may have been a necessary step for various reasons, I think any effective resistance movement today has to bring in all the scattered factions and unite them under one banner.
(Not to mention that middle-class white kids, however pissed off, still have a lot to learn about the real meaning of oppression and resistance.)