I just checked out of an airbnb this morning in Bangkok that had signs posted all over the lobby and elevator that this was NOT a hotel and that if you are caught and not a resident you will be taken to the police. It was pretty uncomfortable watching over your shoulder every time you entered as the security guards eye you up and down. Obviously, the listing didn't mention anything about this.

Edit: here is the sign http://i.imgur.com/dAczEnt.jpg