Some times ago we have a thread about SORBS and many exit nodes were listed in this DNSBL with the attribut "trojan hacked". Conclusion of the thread was: "They have no glue!"
Yeah .. well SORBS is to be taken with a grain of salt.
As do Slashdot, Craigslist, and a bunch of others. People tend to be jerks when they are anonymous .. and yes, it is sort of the "price you pay"Google sometimes does not work with several exit nodes and give you the message "You may have a virus or malware, please clean your computer!" (or something like that).