You know... under new Federal laws he could be prosecuted pretty hardcore.
The problem is finding someone with the time and bucks to prosecute. Then server admins would have to work together to compile enough information on him. But it wouldn't be that difficult. I used to packet sniff my server when he would come by and had tons of data on quite a few of his attacks.
Just have a lawyer file a lawsuit at a local court, subpeona his ISP and have a process server appear at his door. He would have to appear at the court in the city it is filed or hire a local lawyer to represent him.
And I think, what with the way things are right now, if it turns out that he's using zombies to conduct his DoS, the Feds would become quite interested.