Here is a (claimed) account of the dispute from the attackers: http://stophaus.com/entry.php?5-The-Real-story-on-the-New-Yo... .

I got there from the comments on the CloudFlare blog posts, where a user named "STOPhaus" posted taunting CloudFlare, with a link to the stophaus.com website. Apparently it's a meeting place for anti-Spamhaus sentiment and includes such classy stuff as personal information on Spamhaus employees.

Wild stuff, and thanks to CloudFlare for their writeup.