For those who complain about the costs of a lawsuit:
I dunno about the US legal system, but I have a legal protection insurance which covers all the expenses exceeding small amounts (around $500 I think). So it does not matter how expensive the lawsuit gets. Plus, a defendant who is found guilty but cannot pay can be held liable for about 10 years; should he make any more money than needed for his basic living expenses, it can be collected and goes back to the plaintiff.

What's the point in threatening to sue someone when you chicken out, claiming it's too expensive? Are people really believing that a professional scammer is scared by threats on an Internet forum?

@repentance
IANAL, but a lawsuit would at least involve fraud. It would be a nice way to test Bitcoin in front of a court. A few lawsuits with virtual currencies/items have been successful in the past (eg Shanda, Runescape).
And proof? We have the blockchain. If you directly invested with Pirate, he sent you the his address. For the PPT servics, it's the same and just a hop more.