I doubt it - abuse through Tor is a legitimate problem. Wikipedia
   blocks editing from Tor for the same reason.
   There are ideas for solving this though, and it would be cool to see
   more ideas, and more fleshing out of them. Mike Hearn has talked about
   having people make a bitcoin deposit for an account, and after so much
   time of legitimate use, the deposit is refunded. Before that, if it's
   used for abuse, the deposit is kept by the service.
   -tom