[dyn!o]

When you are using anonymous proxies remember that their administrators are forced by law to keep the logs for a specified amount of time (this time vary depending on country specific telecomunication law). Using anonymous proxies does not make you invisible. It makes your IP invisible till the moment the victim conacts proxy administrator - the one you used. Believe me it's not a big problem to reveal any IP, assuming you have legal reasons and cooperate with appropiate governments (e.g. police).

If you want to be really hard to trace then use only Chinese proxies. The goverments in China live their lifes. They don't like to reveal any information outside the country, even if it is an attack on Microsoft site. I haven't heard about any successfull cooperation with Chinese goverments, including evident law violations (international). Of course I don't say that it is good or wrong - I leave that to your opinion.

The world is yours, young hackers...

Regards.