Part of the Critical Mass/TimesUp lawsuit revealed that there's no such law/regulation as keeping to one side or another of the street. Bikes are vehicles in this regard, and about the only special reg is being allowed to ride two abreast just like motorcycles. The city is appealing the outcome (i.e. they lost) so I don't know where that ruling might stand in terms of citing it in Court.

NYC law clearly states that sidewalk riding can be legally done by children up to the age of 14 using a bike with a maximum of 26" wheel diameter. No, I have no idea where they got this stuff from, it's just what's written there, so I think you sidewalk warriors are screwed. I sometimes coast up the curb cut, but always with at least one foot unclipped, so I'm obviously 'not riding'. I've never been accosted by the Heat, so I don't know if that will work.