Then what _can_ we do? Because as it stands, Tor is the perfect tool for criminals, and your stand is "do nothing." An ISP can trace illegal activity to a user, we can't. Even if Tor is considered an ISP in that sense, the rules vary by country, maybe even by provider.

I'm being to think there is no real solution to the problem. As long as Tor serves its purpose of providing uncensored access to the Internet, bad guys will always abuse it, and the operators will almost always be at odds with their ISP. Anything we try to do to block abuse will destroy the very concept of Tor.