I've litrally just 10 seconds ago came away from there wondering how to delist myself. I have 2 IP's both "listed", one of which isnt even a mail server, delisting seemed overly complicated and required jumping through hoops, so i came to the conclusion they were a bunch of inept scammers, and gave up.
edit: Im going to put my neck on the block and put this how it needs to be said: SORBS is a scam outfit.
From some quick research there's tons of complaints about them, it appears theyve been taken to court several times, and the only way to get delisted is to pay either a charity (which people report wont actually get you delisted) or contribute towards some guys legal defence..... who happens to own the site.
If im wrong, someone please correct me, but this stinks of scam to me.