Hehe:)

You folks really do the sub thing. If you are not the owner, not the lease holder, I don't thing you can take any action on it.

However, to be NYC kind of street wise -- if I were you, I would just find a better place, and ensure my right of stay there on paper, then arrange my life there (before I own my own place).

Don't worry about the landlord -- if the guy does not have appropriate paper to stay there, the landlord can simply lock him up to death -- until he calls the police to get out. Don't worry about the sophisticate New Yorkers -- the landlord can just pretend he does not know anything, he can just lock up the rook for, say, a few weeks, then find a dead body there, then he calls the police for investigation and clear up the whole thing and rent it out again.

Nothing matters by the end of day.