According to Twitter sources, there are at least 1,000 people in Zucotti Park right now. Various media outlets are reporting "a few hundred" protesters, but my boots-on-the-ground people are usually very close in their estimations.
The occupiers were as energized as I've ever seen them, despite the heavy police presence breathing down their necks and watching every move. Tensions were high, especially earlier in the day while the celebration was just getting geared up. From Twitter reports, it sounds like there were between 4-6 arrests on the sidewalk near the park. A witness says - via Twitter - he saw one arrestee punched in the head 10-15 times while subdued. You can see some of those arrests in the video above.
Protesters were pointing to two officers who they blamed for starting the altercation, via Livestream. Protester alleges this all started because officer Winski grabbed him and officer Murray shoved him. They are referring to 1st Precinct Commanding Officer Edward Winski, who has had several run-ins with occupy protesters. Last September, he reached over police barricades to detain an Occupy Wall Street protester during a march, and in December arrested protester Justin Wedes as he was passively filming the police.
Michael Moore has joined the crowd at Zucotti Park. If you check out the livestreams I posted earlier, you can see what a good time the group is having. Now if NYPD can chill out...