It would be really bad form to use BGP to advertise a specific route to their hosts and DNS server, and if you're not a Tier 1 provider your advertisements would probably be blocked anyway. While using the main Bogon list isn't really appropriate either, it's a problem that's becoming increasingly common, and a list of stolen routes is almost the right kind of place for such a thing. Obviously it's hard to implement cleanly, without opening up things like a "double Joe Job" attack where the miscreant attacks a web server by joe-jobbing somebody who'd get the server put on the block list. I get a mild version of the spammers-using-my-name attack - spammers sending mail to a closed mailing list I manage, who get bouncegrams from the list-manager saying that their posting is delayed for moderator approval, and if they were from forged addresses I get the bounces from the bouncegrams.