Update (3:01 p.m. EDT): At Washington Square Park, police readied orange nets to corral protesters, NYCLU tweets:
Meanwhile, an impromptu sit-in seems to be underway at Broadway and 21st Street, according to prolific Occupy tweeter Carrie M:
Update (2:51 p.m. EDT): Multiple people on Twitter say marchers have taken over 5th Avenue, around 29th and 30th Street. The emergency services watcher @Breaking911 tweets: "OWS marchers have taken 5th Ave -- pushing back #NYPD officers. Operations req arrest wagons."
Update (2:45 p.m. EDT): This is one of the funnier signs we've seen floating around on Twitter (via @mollycrabapple):
Update (2:42 p.m. EDT): Things got a little out of hand at Washington Square Park. "Trashcans were thrown, barricades were flung, arrests were made during march up to wash sq pk," NYCLU tweeted. Citizen Radio's Jamie Kilstein tweeted this image of protesters taking over a street:
Update (2:32 p.m. EDT): At least two more arrests are being reported, this time in the neighborhood of Washington Square Park, where the wildcat march has stopped to regroup. NYCLU tweeted photos of both:
Update (2:17 p.m. EDT): One of the many smaller marches just passed by The Atlantic Wire's office, heading up Lafayette Street. About 80 marchers accompanied by at least as many cops:
Update (2:02 p.m. EDT): Reuters has a worthwhile story on the white powder incidents. A total of 10 letters have arrived at banks and news organizations, including three Tuesday, "along with notes suggesting the sender sympathizes with the Occupy Wall Street's Day of May 1 protests, police said." The powder, fortunately, turned out to be harmless.
Update (2 p.m. EDT): The next thing scheduled is the Guitarmy march, led by Rage Against the Machine's Tom Morello, departing from Bryant Park right now and heading to Union Square. Timcast is at Bryant Park now.
Update (1:54 p.m. EDT): The Ustream channel Onesabin seems to be offline, but Vice has a good live feed from the wildcat march Downtown, and Timcast is still streaming from Midtown.
Update (1:49 p.m. EDT): The Guardian's Ryan Devereaux tweets this shot of the wildcat march getting underway about eight minutes ago:
Meanwhile, apparently Gilbert Godfrey's up in the mix somehow? That's what Adrian Chen's hearing from Newyorkist.
Update (1:41 p.m. EDT): More suspicious white powder's been discovered, this time at the headquarters of Citi Bank at 399 Park Avenue, @911Buff reports. A hazmat team's apparently on the way.
Update (1:36 p.m. EDT): Someone just got arrested in a pretty rough scuffle between police and protesters at Roosevelt Park, where the wildcat march is staging.
Update (1:30 p.m. EDT): The protest marches are expected to end up at Union Square for a 4 p.m. "solidarity rally," with speakers and bands, before a big march from Union Square to Wall Street. Fast Company's Neil Ungerleider describes what to expect at Union Square:
Expected acts veer towards the hipster end of the spectrum, with Das Racist, Dan Deacon, and Immortal Technique performing. Tom Morello (Rage Against The Machine, Audioslave) and Ben Harper are leading a Occupy Guitarmy protest march as part of the larger Bryant Park contingent that will strum guitars and sing acoustic songs in a giant folk concert that will make its way to Union Square as well.
Instagram user clay_tone shared this photo of the small crowd waiting for things to get started at the square: