Jason Haar wrote: > Why can't SURBL be expanded to support > full URLs instead of just the hostname? That way you could blacklist > "a.bad.domain" as well as "xttx://tinyurl . com/redirect-to-bad-domain"? > Some form of BASE64 encoding would be needed of course, but why not?
Because spammers could easily generate a unique URL for each individual spam. They could then map this back to listings in URI blacklists and use that as a very cheap and effective way to listwash. And they only need to add a single astricked hostname in their DNS server to accomplish this. As a result of this and similar tactics, URI lists would bloat exponentially and this would slow down the propagation of the data to rsync users and to DNS mirrors, as well as bringing the backend processing to its knees. Finally, there is some amount of reputation and registration (even if hidden) associated with a domain due to the fact that a domain *requires* ownership. URLs and subdomains are more ambiguous, which then also makes removal requests extremely subjective and murky process. -- Rob McEwen http://dnsbl.invaluement.com/ r...@invaluement.com +1 (478) 475-9032
