N.Y. Penal Law § 240.10

§ 240.10 Unlawful assembly.\n A person is guilty of unlawful assembly when he assembles with four or\nmore other persons for the purpose of engaging or preparing to engage\nwith them in tumultuous and violent conduct likely to cause public\nalarm, or when, being present at an assembly which either has or\ndevelops such purpose, he remains there with intent to advance that\npurpose.\n Unlawful assembly is a class B misdemeanor.\n