I see 840 BTC pledged so far.  That is certainly enough to pay for consultation with a lawyer.

I'm not sure why someone hasn't made a legal threat to put pressure on hashking to pay back.  You guys know who he is IRL.  He is most likely in control of 4000+ BTC, rental properties and other assets.  mining4fun11, who was posting that they had nothing worth going after, was outed as a hashking sockpuppet.

Are you guys too embarrassed you invested in an obvious scam?

Are your own finances too shady to put your real name on some legal documents against him?

Stop with the childish threats of violence and use the legal system.  If he has assets, you may be able to recover something.  If not, you weren't going to get anything regardless.