I used to have a domain which had its URL included in a completely unrelated spam. A blacklisting organisation (voluntary, I think) contacted my ISP to tell the

I used to have a domain which had its URL included in a completely unrelated spam. A blacklisting organisation (voluntary, I think) contacted my ISP to tell them I was going on their list unless I could explain what had happened. I spent a very long, depressing email conversation explaining to them exactly what database poisoning was, and why the spammers would include unrelated URLs in a spam email. So many ways to fail at that kind of endeavour... (The URL was for my open source project. Clearly, they didn't even check the webpage before issuing their threat.)