Spamhaus maintains a running list of the worst spammers, biggest spam producing countries, and the networks that are the most tolerant to Spam. Interesting in this latest iteration is the fact that while Microsoft has cleaned up their act and booted spammers from their domains, those spammers appear to have fled to Google's networks, placing the onus on Google to uh, not be evil. Google is now ranked fourth on the Spamhaus network list. Brian Krebs of the excellent Washington Post Security Fix blog explains:Google says they've already begun "implementing improvements to minimize the impact of the issue." Other notable names on the list include Sprint and Verizon, who appear at numbers eight and nine on the list, respectively.

"Although all networks claim to be anti-spam, some network executives factor revenue made from hosting known spam gangs into corporate policy decisions to continue to sell services to spam operations," says Spamhaus. "Others simply decide that closing the holes in their end-user broadband systems that allow spammers access would be too costly to their bottom lines."