On October 1, 2011 the NYPD arrested 700 people on the Brooklyn Bridge. Three days later many of those arrested filed a lawsuit contending that police had tricked them onto the bridge only to trap and arrest them, a tactic called 'kettling'.

Among protesters arrested that day was Malcolm Harris, the activist who is now fighting a NYC prosecutor's subpoena to Twitter for account information likely connected to his 10/1/11 disorderly conduct charge.

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Today US District Court Southern District of New York Judge Jed Rakoff ruled that the suit against the arresting officers can go forward, writing:

What a huge debt this nation owes to its "troublemakers." From Thomas Paine to  Martin Luther King, J r., they have forced us to focus on problems we would prefer to downplay or ignore. Yet it is often only with hindsight that we can distinguish those troublemakers who brought us to our senses from those who were simply troublemakers. Prudence, and respect for the constitutional rights to free speech and free association, therefore dictate that the legal system cut all non-violent protesters a fair amount of slack. 

These observations are prompted by the instant lawsuit, in which a putative class of some 700 or so “Occupy Wall Street” protesters contend they were unlawfully arrested while crossing the Brooklyn Bridge on October 1, 2011. More narrowly, the pending motion to dismiss the suit raises the issue of whether a reasonable observer would conclude that the police who arrested the protesters had led the protesters to believe that they could lawfully march on the Brooklyn Bridge’s vehicular roadway. 

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The plaintiffs assert, in effect, that they attempted at all times to follow the NYPD’s instructions and that they had every reason to believe the police were permitting them to enter the bridge’s vehicular roadway. The police, by contrast, assert that they expressly warned the marchers that entering the bridge’s vehicular roadway would lead to their arrest. In assessing these competing contentions, the Court, at the parties’ behest, has examined two videos of the events.

This is where it gets really interesting. One of the videos comes from a protester, and the other, from one of the NYPD's TARU cameras, which are almost always filming at political demonstrations in the city. 

Plaintiffs’ video, apparently filmed by a protester, shows a uniformed police officer speaking into a “bullhorn” approximately fifteen feet from the camera, at the Manhattan entrance to the Brooklyn Bridge. Many protesters chant and clap. A whistle blows in the background. A viewer who listens closely can understand some of the officer’s words over the protester’s persistent chants, but not enough to perceive the officer’s meaning. Once the officer finishes speaking, he turns his back to the protesters and returns to the line of officers blocking access to the vehicular roadway. After a few moments, the line of officers turns and proceeds onto the vehicular roadway, followed, at a distance of at least ten feet, by hundreds of protesters.

The defendant’s video, filmed by the NYPD’s Technical Assistance Response Unit (“TARU”), is shot from behind the officer speaking into the bullhorn. In the TARU video, the viewer can clearly hear the officer tell protesters, “Ladies and gentlemen you are obstructing vehicular traffic. If you refuse to move you are subject to arrest.” The officer later says, “I am ordering you to leave this roadway now. If you do so voluntarily, no charges will be placed against you.”

It appears that some of the protesters near the bullhorn can hear these warnings, and one at the front asks the officer what offense the officers intend to charge. Others standing farther away, however, appear not to hear the officer or even notice that he is has addressed them. After the officer has finished delivering his warnings and rejoined his colleagues blocking the entry to the vehicular roadway, the demonstrators closest to the camera lock arms. The officers – followed almost  simultaneously by the demonstrators – move in the direction of the bridge’s vehicular roadway.

Photographers run into the space between them to photograph the demonstrators. Both the demonstrators and the police officers remain calm and restrained. Other than the initial warnings given by the officer with the bullhorn the officers and demonstrators do not appear to communicate.

The OWS plaintiffs argue that because the NYPD possesses loud amplifier systems, for example the LRAD, but didn't use them, the department didn't make a real effort to inform people that they were risking arrest.

The SAC alleges that though the NYPD possesses sound equipment capable of projecting a message over several blocks, it did not deploy that technology in this situation and the great majority of the marchers thus could not hear the directives that the officer with the bullhorn gave shortly before officers ceased blocking the vehicular roadway. Other than the warnings issued from the bullhorn, the officers allegedly made no effort to stop marchers form entering the roadway. 

Most of the marchers therefore believed, according to the Second Amended Complaint, that they had the NYPD’s permission to use the vehicular roadway to cross the bridge. Of the ten identified plaintiffs bringing this action nine allegedly did not hear any warning that they could not enter the vehicular roadway and some of believed that, when the line of officers blocking the entrance to the vehicular roadway turned and started to walk forward on the roadway it was a signal that the NYPD intended to permit marchers to proceed by that route.  

Allegedly, two of the named plaintiffs, Michael Crickmore and Brooke Feinstein, walked onto the vehicular roadway alongside police officers, who made no attempt to warn them about the illegality of their actions. After approximately 700 marchers entered the vehicular roadway, the police officers who had proceeded ahead of the demonstrators stopped. Although one officer spoke into a bullhorn, the SAC alleges that, given the noise, those marchers who were more than a few feet away allegedly could not hear that officer.

Officers then blocked all forward and backward movement by the marchers. Using orange netting to trap the marchers, the police then arrested the marchers who had entered the vehicular roadway. Officers handcuffed marchers, took them into custody, and processed and released them, giving each a summons that indicated that the officers had seen the marcher commit one or another offense, such as failure to obey a lawful order.

The SAC also alleges that the City has a policy, practice or custom of arresting large groups of protesters in the absence of probable cause in order to disrupt mass demonstrations.

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In the context of peaceful demonstration, the First Amendment affects the determination of when an officer has probable cause to arrest under the Fourth Amendment. The Supreme Court has long held that in such a context laws and regulations must “give citizens fair warning as to what is illegal.”

The Judge then unpacks the events in light of the plaintiffs' claims and the defendants' petition to throw the lawsuit out. He decides that the suit against officers for improper arrests can go forward, but tosses out the claims against the City and Police Department for failing to adequately train officers:

In sum, for the reasons stated above, the Court denies defendants’ motion to dismiss plaintiffs’ claims against the officers who arrested them, but grants the motion to dismiss plaintiffs’ Monell claims against the City, Mayor Bloomberg, and Commissioner Kelly.