More damage than spammers? I see you've never run a mailserver. I have and I know that Spamhaus are one of the good guys doing a hard thankless job, risking lawsuits and threats, in order to keep email as a useful tool. Spamhaus' RBL is the most reputable of all of them, thanks to years of hard work and sacrifice.
The only people who don't like Spamhaus, in my view, are those ISPs who were happy to make money from selling connectivity to spammers while pretending in public that they hated spam. Them, and people who don't understand what Spamhaus do, like the author of this article, and who think Spamhaus are to blame for their troubles.
As one who has worked in the trenches as a mail admin (small potatoes, granted: a few small clients and a couple of small hosting companies), my observation has been than customers bitch way more about the MX servers which reject mail from our servers than the amount of spam in their own in-boxes. They don't give a shit that the recipient is rejecting legitimate mail -- they blame us for their problems. All because some asshat with a copy of TheBat! signed up and managed to send out a couple hundred "Russian bride" spams before we were alerted and nuked the account. I could probably fund a semester of college for some random kid with the time I've been paid to waste on de-listing and convincing idiot admins that one of their customers really wants to get mail from one of mine.
Sure, 99.9% of email hitting the typical in-bound relay is spam, but CPU, RAM, and disk I/O are cheap. Do per-inbox statistical filtering and let the user decide what spam is. Better yet, let client-side filters do the work. Do you think any person would stand to allow a US Postal carrier decide what was junk mail and then not deliver it? People just need to buck up and put in a little of their own effort.
I haven't used an RBL (even if its just one in a battery of weighted tests, such as with Spam Assassin) due to my loathing for the vigilante nature of the RBL scene as a whole. If you operate an RBL -- fuck you. If you are an admin that rejects mail based solely on being listed in RBLs, then fuck you, too. I know I sound like an asshole myself here, but the existence of RBLs has caused me and various mail end-users way more pain than any spammer has.
Bitter? Nah.
As a mail admin, I want to throw SMTP out the window. It wasn't spammers that killed the protocol, but rather the growth of use of RBLs.
Rant aside, I do have a question to contribute to the discussion: Has one of the larger RBLs ever listed one of the huge mail providers (Gmail, MSN/Hotmail, Yahoo?) for any length of time? I know I've gotten spams and scams from all three.
The only people who don't like Spamhaus, in my view, are those ISPs who were happy to make money from selling connectivity to spammers while pretending in public that they hated spam. Them, and people who don't understand what Spamhaus do, like the author of this article, and who think Spamhaus are to blame for their troubles.