The NYC police and firefighters don't have to worry about barricades, or someone telling them when and where they are allowed to protest.
From today's New York Times:
And in recent weeks, the mayor has been drawn into another protest battle, with firefighters and police officers who have trailed him at his public events, holding loud and sometimes raucous demonstrations. Last week, they even gathered outside his home at 1 a.m., clearly violating the city's noise code by yelling loudly and at length.During at least two other protests, police officers and firefighters moved freely without barricades, at times blocking traffic in the street. A group of police officers and firefighters also swarmed the mayor outside a community meeting, forcing his detail to hustle him into his S.U.V., which was momentarily blocked before it pulled out.
No firefighters or police officers were arrested at any of these events. By contrast, during that same time, four women were arrested after trying to hang an antiwar banner from a hotel window in Midtown, and four other protesters who erected a tent near the south end of Central Park to protest Bush administration economic policies were arrested and detained for hours. The Police Department said that police officers and firefighters had not been given any special treatment.
The city has been signaling that it will deal with convention protesters forcefully, permit or no permit.