That’s a good question...when does using your first amendment rights to speech and peaceable assembly cross over into barging in on other’s right not to be molested? Maybe they can charge them with some excessive noise violation.
Marching in a street and in a park without a permit is against the law in NYC. They have at least broken these laws without arrest.
The existence of free speech zones is based on U.S. court decisions stipulating that the government may regulate the time, place, and mannerbut not contentof expression.
See Free Speech Zones
http://en.wikipedia.org/wiki/Free_speech_zone