So what, you say?
They're members-only mailing lists. You can't post to it unless you go through this ridiculous process of verifying your email address. So it joined them all first (GNU Mailman), and then spammed them all. :-(
Any solution I can think of sucks:
-- ban this email from each list. 7 identical operations. Until the next email address.
-- ban the spammer's domain from my mail server. (shit, what's the postfix config again? Hate mail) Until the domain name changes.
-- make the mailing list fully moderated. I'm not responsible/available enough for that. Kills community/discussion too.