Update (7:51 p.m. EST): Things continue peacefully with protesters walking on the pedestrian walkway on the bridge, and we're going to sign off for the evening. A few loose ends:

  • The Times follows up on its report on Brandon Watts, the protester arrested in the police raid on Zuccotti Park Thursday afternoon.  He was charged with grand larceny for taking a deputy inspector's hat, and attempted assault for throwing a battery. The police gave the paper this statement:

Mr. Watts climbed up on a wall inside Zuccotti Park and began throwing objects at officers outside the barricade along Liberty Street, starting with pieces of a plastic pen. He then threw a AAA battery, and motioned to officers that he was ready to fight. The officers ignored him.

Mr. Watts went up to the officers, grabbed the barrier between him and them and began pushing and kicking it, shoving it agains the officers. Mr. Watts grabbed a deputy inspector's hat and ran back into the park. The officers ran after him. He resisted arrest, kicking officers, and when he was brought down, he struck his head, causing bleeding. He was taken to Bellevue Hospital Center, where he was treated but not admitted.

  • The day's arrest count reached higher than 200 all told, reports the New York Daily News. That report also says several hundred protesters have made it to Brooklyn, but police were blocking some from entering the bridge in Manhattan. 
  • There's an aerial video stream (unfortunately not available for embed) broadcasting images of the bridge march with no editorial chatter, except from the pilots.

Update (7:27 p.m. EST): Village Voice's Nick Pinto tweets a much better photo of that "99%" projection, this time on the Verizon building:

Update (7:20 p.m. EST): We're getting some official estimates of the crowd size, courtesy of Russia Today:

Update (7:01 p.m. EST): Somebody managed to project "99%" on a building adjacent to the bridge. It's three stories high, but unfortunately poorly captured in this screengrab from the live feed:

Update (6:55 p.m. EST): Thousands of continue to stream across the bridge at a slow pace, keeping on the sidewalk. Meanwhile, The New York Times brings word that Brandon Watts, the protester who police arrested in a dramatic Zuccotti Park raid earlier has been charged with larceny and attempted assault.

Update (6:36 p.m.): These little moments do remind one of the truly pressing issues in life (via David Horvitz Twitter):

Update (6:30 p.m.): Protesters have walked onto the pedestrian walkway on the Brooklyn Bridge, reports Breaking911. Meanwhile, The New York Times reported that 60 people had been arrested at the entrance to the bridge, then it tweeted that "scores more" had been taken into custody by police.

Update (6:17 p.m. EST): New York City Councilman Jumaane Williams has reportedly been arrested, along with "dozens of union members after they sat on the ground on Centre Street," according to The New York Daily News.

Update (6:14 p.m. EST): Arrests are starting on the Brooklyn Bridge, beginning with a union president, per Ed Schultz:

Update (6:09 p.m. EST): A march is departing Foley Square for the Brooklyn Bridge. Earlier reports said 100 officers had massed there. Probably more by now. Live feed narrator Tim Pool says the rumor is police are standing shoulder-to-shoulder on the bridge.

Update (5:46 p.m. EST): CBS has a live feed going from its helicopter. We grabbed a screenshot:

Update (5:43 p.m. EST): Turns out the airspace is not closed. NBC tweets its pilot misunderstood directions from the control tower and was not actually ordered out of the area.

Update (5:37 p.m. EST): Occupy Wall Street estimates 10,000 people in Foley Square. The march from Union Square just arrived and the narrator said, "easily 10,000, probably more." Several unions are on hand, and people are massing across the street outside the square, unable to enter because it's too crowded. Meanwhile, NBC New York reports police have closed the airspace over the protest and told its chopper to move on.

Update (5:27 p.m. EST): Throwing back to Thursday morning, the New York Observer sends along this photo it posted earlier Thursday of Ray Lewis, the retired Philadelphia Police captain, in flexi-cuffs. That there is a sight you don't see every day:

Update (4:50 p.m. EST): The march has started moving and is making its way toward Foley Square, where many more protesters are reportedly gathering. Breaking911 tweets: "2,000+ Protesters on Greenwich Ave & 6av Southbound in the Street Against Traffic." Meanwhile, Allison Kilkenny tweets that the Foley Square subway station has been closed. The live feed reports the square is already full of people, and this Twitter photo from Allison Rae seems to support that: 

Update (4:40 p.m. EST): Mayor Michael Bloomberg and Police Commissioner Ray Kelly had a press conference Thursday afternoon at Bellevue Hospital and gave some specific information on the day's events so far. The Village Voice has a good summary:

Kelly reported that there had been 177 arrests today, five for assault. Seven police officers were injured; five had liquid thrown on them and one had a hand injury.

Kelly described the incident in which the officer's hand was injured at Zuccotti. He said that there was an attempt to arrest people who had moved barriers, and during that situation an object was thrown at the officer. Kelly added that the officers had been released from the hospital.

Bloomberg put the estimated number of protesters at less than 1000, saying that it was "hard to tell."

"Rest assured that the NYPD is trained for these situations," he said. "If you're here in the city and you want to protest, you can."

Update (4:36 p.m. EST): Protest or no, the game must go on. These chess enthusiasts in Union Square didn't care they were in the middle of a gigantic political rally (via Thomas Macmillan on Twitter):

Update (4:23 p.m. EST): Protesters are standing off against the police at Fifth Avenue and 14th Street. Breaking911 reports "multiple arrests" and police calling for backup.

Update (4:15 p.m. EST): The protesters have left Union Square and are heading for Foley Square near City Hall where an even bigger rally is scheduled for 5 p.m. The Union Square get-together was pretty huge by itself. AM New York tweets there are "easily thousands" of people. Russia Today's Lucy Kafanov estimates the crowd at "over 3k." She also shares this photo of the crowd marching down Fifth Avenue:

Update (4:05 p.m.): For those keeping track, the arrest total for Thursday is up to 175, per MSNBC.

Update (4:02 p.m.): Anne Hathaway's there, holding a "Blackboards not Bullets" sign, courtesy of Elana_Brooklyn:

Update (3:50 p.m.): After a student made a speech about a thwarted demonstration at Brooklyn College, another takes the stand to propose a march to Madison Square. Then a third announces a campaign against student debt. Meanwhile, the crowd at Union Square continues to swell, as this photo from Liliana Segura shows:

Update (3:33 p.m.): The march from Zuccotti Park has made it to Union Square.

Update (3:30 p.m.): Earlier on Thursday, one local Fox News station reported that the Occupy protesters wanted to shut down the subways, which with their numbers they could do. That's not the kind of thing New Yorkers take lightly. But The New York Times pointed out in a blog post that the report wasn't exactly accurate. As we've noted here before, protesters have expressed their intention of "occupying" the subway and sharing stories with riders. Still, as the 3 p.m. "lunch" plan to take to the subways gets underway, many on Twitter are nervous about their impending commutes. Blogger and Esquire columnist J. Kirkland tweeted: "I don't understand what OWS is going to do on the subway…Shouldn't they be protesting at car services instead?"

So far, some reports of occupations at subway stations have come in, including the 23rd Street A/C/E, Chambers Street, 116th Street, and of course, Union Square. The website for New York's MTA shows delays along the 1/2/3 line but otherwise good service. It attributes the delays to signal problems at Tremont Street. But if enough people crowd into the system it could cause hassles whether they mean it to or not.

Update (3:12 p.m.): Kids in the Hall fans will chuckle at this alternate view of the Union Square rally from April Wright. We did. Also, it's not exactly a wall-to-wall crowd there yet, apparently.

Update (3:05 p.m. EST): Students who walked out of New York classrooms have already filled Union Square, as Occupy Wall Street protesters make their way from Zuccotti Park to join them. Elana_Brooklyn tweeted this photo of "wall-to-wall students" demanding free tuition in Union Square:

Update (2:53 p.m. EST): We hate to send you away, but the Daily News just posted a series of photos of the protester arrested in Zuccotti Park that are worth a quick look. It's pretty graphic, though, just so you know. The New York Times, meanwhile, points out that the guy who was arrested apparently flicked a cap off a cop's head. That's one way to get the police mad at you.

Update (2:32 p.m. EST): Protesters have begun marching to Union Square for the 3 p.m. rally. Meanwhile, NYCLU and the Daily News both report that officers are massing on the Brooklyn Bridge in anticipation of a march there later.

Update (2:28 p.m. EST): The cordon around the park has eased. Reports on Twitter say police are allowing people out, and Bruner confirms via text. New York Daily News tweets that the injured cop "was cut on hand by a thrown glass object during #OWS #N17 protests in NYC." As for the injured protester, rumor on the ground is that he wasn't hit by a baton, as first thought, but that he fell when police arrested him forcefully. He had reportedly been kicking barricades earlier.

Update (2:05 p.m. EST): It's not great quality, but someone showed the live feed a picture of the guy that got hit:

Update (2:01 p.m. EST): The park is now completely sealed. Occupy spokesman Patrick Bruner reports via text "It got kettled. Medics aren't being allowed in."

Update (1:53 p.m. EST): New York Daily News tweets: "Protesters running, jumping barricades amid Zuccotti Park mayhem at this moment." And later: "At least 100 NYPD cops in riot gear now in Zuccotti Park." Then there's this:

Update (1:50 p.m. EST): Police are swarming into Zuccotti Park and a paddy wagon has arrived. The live feed guy says cops now outnumber protesters. According to Breaking911, an officer has been stabbed in the hand.

Update (1:44 p.m. EST): Breaking911 tweets: "NYPD is screaming for backup forthwith in Zuccotti Park. Unknown condition." According to Boyle's tweet, "cops are trying to clear Zuccotti Park. Very tense. Saw one man in the middle badly bleeding from the head."

Update (1:43 p.m. EST): Break didn't last long. Police have entered Zuccotti Park and closed it off, according to the live feed. Protesters are yelling on the broadcast that police won't let people out of the park. "People putting their arms in the air and chanting "peaceful". Cops flooding park," tweets New York Daily News reporter Christina Boyle

Update (1:35 p.m. EST): Things around Zuccotti and the Wall Street area seem to have settled a bit, with many taking a lunch break of sorts. Protesters and police are girding for a 3 p.m. student rally at Union Square, which is set to coincide with previously announced plans to take the demonstration to subway stations citywide.

Update (1:11 p.m. EST): Student Activism tweets news of injured police officers it attributes to CNN: " 'four officers transported to hospital,' doesn't say it was to check out 'unknown liquid' they got splashed with. The liquid, according to a two-hour-old Breaking911 tweet, appears to be vinegar: Manhattan: Broad St & Beaver St #EMS treating 4 #NYPD officers with vinegar thrown in their faces. Multiple arrests made."

Update (12:58 p.m. EST): One of the people arrested earlier turns out to be Keith Gessen, the editor of literary magazine N+1. Crain's New York reporter Daniel Massey photographed him, and many on Twitter identified him. There's also video of his arrest, if you're so inclined.

Update (12:49 p.m. EST): Breaking911 reports "heavy clashing" between police and protesters, and shares this photo:

Update (12:42 p.m. EST): Breaking911, the unofficial New York City emergency services Twitter stream, reports: "Large Group Marching West Bound on Exchange Place Between Broadway & Lliberty Street." Meanwhile: "Units Req a Prisoner Wagon at Exchange Pl & Broadway."

Update (12:29 p.m. EST): Protesters report on Twitter they're penned by barricades in at Broadway and Wall. Meanwhile, police have arrested at least four at 80 broadway, where Daily News reporter Matt Lysiak says they're "losing control of the crowd."

Update (12:26 p.m. EST): Comedian John Knefel tweets this video of Ray Lewis, the retired Philadelphia police captain, getting arrested earlier Thursday.

Update (1207 p.m. EST): Police have confirmed 75 arrests, CNN reports. Streets around Wall Street remain closed, and "residents and employees are using identification cards and badges to access Wall Street areas near the [Stock] Exchange."

Update (12:01 a.m. EST): Two groups of protesters left Zuccotti Park a few minutes ago, one heading up Broadway and another on Cedar Street. Police initially let the Broadway march through a set of barricades, but it seems they've been turned back at Rector Street and are heading back toward Zuccotti.  

Update (11:43 a.m. EST): Earlier Thursday, as police were arresting people en masse near Wall Street, reports came over Twitter that a woman in a wheelchair had been arrested. Now, UK Observer reporter Paul Harris tweets that the police wanted to arrest her but couldn't figure out how to transport her, so they ticketed her instead. He shares this photo:

Update (11:30 a.m. EST): The chaos around the barricades has ended and things are calm in Zuccotti Park again. But the barricades along the south side have been removed.

Update (11:12 a.m. EST): Holy moly! Protesters in Zuccotti Park, where many marchers have congregated for a midday assembly, have started tearing down the barricades which have surrounded the park since Tuesday. They outnumber the police, but officers have stormed the protesters and are using their billy clubs to push them back. The live feed has a front-row seat:

Update (11:08 a.m. EST): Reports of more arrests continue to come over Twitter. Salon reporter Justin Elliot Tweets, "National Lawyers Guild guy tells me at least 80 arrests this morning. Nypd flack won't confirm." The last confirmed total from police headquarters was 50, but that was about an hour ago. Meanwhile, NBC New York posted this raw video of protesters getting arrested:

Update (10:51 a.m. EST): Protesters couldn't get in front of the New York Stock Exchange en masse to disrupt trading, but ironically, that's where police are loading the arrestees onto buses, reports the New York Daily News. "One man being led away in cuffs just shouted 'We'll be back, Stock Exchange.' "

Update (10:43 a.m. EST): After multiple Twitter reports that police had deployed a long range acoustic device (LRAD) to control the crowd near Wall Street, Russia Today shares photos from a protester named Joshua Paul showing what appears to be the device. We're no LRAD experts, but this looks a lot like the Google Image search:

Update (10:37 a.m. EST): Some surreal images have started coming out of the morning's protests, like this one of a police officer confronting someone in a Cookie Monster costume (via @Matthew4300 on Twitter):

And this one, in which protesters absconded with a police barricade (via @JoshHarkinson on Twitter):

Update (10:15 a.m. EST): After more arrests at the corner of Beaver and William streets (for an estimated 50 in total, according to the Daily News), the main group of protesters have decided to move from the intersection of Nassau and Pine after they couldn't get in front of the New York Stock Exchange on Wall Street, reports the live feed. They're reportedly heading to Broadway. Animal New York tweets this photo of the view down Pine Street a few minutes ago:

Update (9:34 a.m. EST): The opening bell of the New York Stock Exchange rang on time after erroneous reports from before the opening that it had been delayed.

Update (9:25 a.m. EST): The live feed and Twitter reports both say a retired Philadelphia police captain named Ray Lewis has been arrested. Lewis joined the protesters at Zuccotti Park on Tuesday night, the New York Observer reports, and implored New York Police officers to join the Occupy crowd, holding a sign that said, "NYPD Don’t Be Wall Street Mercenaries." On Thursday morning, the Occupy Wall Street Twitter stream posted this photo of Lewis:

Original: Occupy Wall Street's day of big planned action started as a crowd estimated at between 500 and 1,000 set off to "shut down Wall Street" as part of a day of protests, and arrests have already begun. Crain's reporter Daniel Massey tweets that "Several dozen who sat in street being arrested at William and pine cops dragging protesters away." On one of the occupiers' UStream video feeds, police can be seen fastening zip-ties around the wrists of several protesters as the crowd chants "this is a non-violent protest." On Twitter, several others estimated the arrest total at 30.

Minutes earlier, police blocked off Wall Street and are faced protesters who have crowded into the street outside the barricades. The protesters' plan is to make a day of it, starting with the march downtown (which they're calling "breakfast") and moving to subway stations in the five boroughs during the afternoon (dubbed "lunch"), then culminating in a big 5 p.m. rally at Foley Square, near city hall, and another (dinner) march to an unspecified bridge -- the Brooklyn Bridge is the closest.

For protesters, things are going pretty well (aside from those arrested). The Occupy Wall Street Twitter stream posts this shot of what it says are 400 people chanting "this is a nonviolent protest:"

Others have been having a harder time. The New York Daily News reports lots of Wall Streeters can't figure out how to get to work, with all the crowds and barricades blocking the way. "I'm all turned around. How can I get to Chase Bank," reporter Erik Badia heard one man ask a police officer. The officer told him. 

It's going to be a long day, especially for those involved in the protests and those in the neighborhoods where they're happening. To keep up, we'll be providing updates here. But there are a couple of online resources you might also want to bookmark for quick reference:

The Occupy tech team made this Occupy Map, which is supposed to track the protesters' movements via updates sent in by those on the ground. 

And there's a good UStream going, which helped with our coverage of the return to Zuccotti on Tuesday: