"It wasn't just one, but Mars omits violence, breaking and entering is materially impossible, anyone who'd rather not deal with anyone else can mutually cease to exist to that person, the bank does not operate in such a way as to permit theft, and the city is set up to make noise complaints and littering and so on a nonissue. I have not been particularly circumspect about who I allow to live there, and there has not been a problem, and if there is, I will patch it."