Spammers hate these guys. I mean, they really hate these guys. SPEWS is the Spam Prevention Early Warning System, an anonymous service that keeps lists of spamming Internet sites and service providers. They provide these lists to anti-spam services, to maintain an up-to-date blacklist of spammers. And the spammers really hate these guys.
In fact, this URL, http://www.spews.org , isn't even the location of SPEWS. No one knows where SPEWS is maintained, but there have been many efforts to try to find out. The spews.org site was maintained until 2002, when constant attacks from spammers finally forced the administrators to shut it down. The best places to keep up to date with SPEWS activities are the moderated newsgroup news.admin.net-abuse.blocklisting (NANABL) and the unmoderated newsgroup news.admin.net-abuse.email (NANAE). Be aware, however, that NANAE is the home of some of the worst flame wars and newsgroup spam attacks on the entire Internet (even worse than the alt.religion.scientology attacks!). Tread lightly into NANAE, and take anything you read there with a degree of skepticism.
However, it's a given that no matter how vicious and heated the flame wars on NANAE are, spammers are worse. That's why SPEWS is still popular and widely used by many ISPs and spam filters: they are providing a valuable service to the Internet.
And the spammers really hate these guys.