The DAO hacker will not dump because dumping would reveal his position, then the exchange would pass this info to authorities. DAO hacker dump is FUD.
Tell me, what law did he break? Following a Smart Contract with "code is law" rules? I would be very interested to see that lawsuit develop.
The only ones who - in my opinion - did anything illegal are the ETH-founders who forked to safe their own money.
I am very interested in see the law suit against the Ethereum community. But maybe there is no ground. The hacker still has all the Ethereum.