UNION SQUARE, 9:30 P.M.--I am heading home and walk into yet another scene of confrontation. Most of a carnivalesque demo known as the NoRNC Street Party was arrested about two hours ago. According to a participant who escaped, Stuart, 39, the march was just starting, making its way north down the sidewalk with room for other pedestrians to pass, when suddenly police put up barricades and diverted the marchers onto 16th Street, trapping them between Union Square East and Irving Place. Among the nearly 200 arrested were an entire marching band and some Missile Dick Chicks.

The sudden pincer move has been the most commonly seen police tactic this week. NYCLU put out a press release tonight denouncing what they call "bait and switch" tactics by police, who appear to be negotiating or to allowing people to walk on the sidewalk, only to suddenly trap them and arrest them seemingly indiscriminately. This happened with Critical Mass on Friday, PPEHR yesterday (no mass arrests, but the crowd was suddenly divided), and both at Ground Zero and Union Square today.

This lack of good faith from police makes situations volatile and dangerous. I have not yet witnessed an act of physical provocation from protesters (people have yelled some stupid things). In every case the police have acted without communicating first.

According to Reality Check, over 800 people (NYT says 900) have been arrested today, including nuns, veterans, and students, at Ground Zero, Fox News HQ, a Halliburton breakfast, Hummer of Manhattan, and especially at Herald Square.