Have you ever considered using SPEWS (Spam Prevention Early Warning System)? They regularly publish lists of known spamhausen in several ways including Procmail filters, router DENY tables, and records you can use as DNS zone files. SPEWS is quite effective at helping you shunt off much of the spam before you receive it.
I'm not SPEWS and don't represent them, but my company uses their service and is happy with it.
Being at sea much of the time and using a satellite phone system for the internet means spammers cost me considerably.
Spam reduces overall national productivity as company employees have to spend so much time deleting it. It would help if the laws concerning mass faxes were applied to spam. Plus, no one with above double digit IQ would ever buy anything that came from a spammer.
Spammers and those who supports them should be squatted over a belt sander, or over a blender set on puree.