Somethings that may help you are to see what his home states laws are about this sort of thing. The A.G's. office can help there. I would also contact the mods/ owners of the sites where you know him to be and let them know. Some of those folks frown on rip offs and will contact the person and/or delete his account. I know that there have been those that have gone to and are still in prison for doing the rip off through the mail. You just need to find the person at the postmaster's office that wants to do what they're hired for.
VISUALIZE WHIRLED PEAS
MAY THE HORSE BE WITH YOU!!!