extortion is a federal and state crime punishable by up to 20 years in prison (in USA).
So call the cops...
LOL

if it was done in real life, sure. The capabilities of police to unmask this individual on the internet, who probably doesn't even live in the same country... they'd subpoena BitcoinTalk for information requests. There's a lot of barriers there, and I wouldn't want the police knocking down the door of a forum I like a lot, and has provided a lot for me and for many others. But if the forum isn't thwarting provable criminal activity, what has it become? What will the community turn into?