Legal action would be a waste of time for such a small amount, I know from personal experience, but good luck with that. Can't say I feel bad about a loan shark not being paid back, OP was charging rates that would be considered illegal in many parts of the world. He wasn't even necessarily scammed, someone just defaulted on a loan, happens everyday in America.
Have it in mind that this was a no collateral loan we are dealing with, which is given to someone who is a complete stranger over the web, so the high interest rate would be more than reasonable.
On top of that, if someone was totally uncomfortable with the interest rate that is clearly stated in the announcement, then why would they go ahead and request for the loan