I feel sorry for you. It sucks that someone would choose to stoop this low. At least we all know not to buy/trade from any of the mentioned culprits in this thread.
As for something being done unless the authorities in California or that internet fraud force someone mentioned acts I don't think much can happen. Sadly it seems like a life lesson of getting tougher.
Hopefully though someone can give this guy a taste of his own medicine someday, and take him for what he's worth