wtf? have you contacted his host? we have this problem everyday. contact the host, explain that your copyrighted material is being used by the guy. if they do nothing about it (this almost never happens) then contact the upstream provider.
if you want to be more formal:
http://www.authorslawyer.com/c-pir-l2.html (to the infringer)
http://www.authorslawyer.com/c-pir-l3.html (to the host)