A little more than two years ago the NYPD arrested 732 demonstrators on the Brooklyn Bridge in what would be the largest mass arrest of the Occupy Wall Street movement in New York. But how many of those charges—mainly for disorderly conduct or obstructing governmental administration—stuck? The current tally: 680 dismissals (195 at the request of the City, 40 by judges, and 445 more ACD); 21 cases where charges were dropped; 6 guilty pleas to disorderly conduct; 2 acquittals; 1 plea resolved in another case, and 17 no-shows. Five protesters were convicted of the charges levied against them.

“From an administrative and justice perspective, this was obviously a challenge,” Manhattan DA Cy Vance told Colin Moynihan. “I’m proud that the office handled the cases in a fair and evenhanded way.”

The cases were handled by the DA's "mass arrest coordinator," with the help of three prosecutors and four paralegals. The National Lawyers Guild, which represented 662 of the protesters, assigned 45 volunteer attorneys who made 1,500 appearances in court.

A class action suit filed by the protesters against the City, alleging that the NYPD lured them on to the Brooklyn Bridge to be arrested, is still working its way through the legal system.

It's unclear how much the arrests and their ensuing prosecution cost taxpayers, though the NYPD spent $17 million in overtime on Occupy-related events in 2011 (the department budgeted $614 million for overtime this year [PDF]).

Mass arrests during demonstrations are regarded by experts as having a profoundly chilling effect on free speech [PDF].

1,806 people were arrested during the 2004 GOP convention, and around 90% of those cases were dismissed. Taxpayers shelled out at least $8.2 million for the City to defend the ensuing lawsuits, but the real number is likely much higher: the most recent figure available is from 2008.