On copyright and trademarks, there are some nasty pitfalls around the setting for a series of works. If I recall correctly, Marion Zimmer Bradley got caught by that over her Darkover series. Copyright covers a specific work, such as "Amazon Queens of Poserworld". You need other methods to protect the idea of Poserworld. Yes, the address is weird. I'm not a lawyer, and I'm especially not competent in US or Californian law, but combined with the other elements it may be criminal--something like wire fraud. It would be possible to make life very unpleasant for this guy.