Hack'n'spam

Hack'n'spam
         

<p>One of the perennial problems for spammers is finding what the intelligence community refers to as 'clean skins': identities that aren't associated with known bad actors. For spammers, the problem is two-fold: they want their emails to originate from netblocks that aren't known to be spam-infested, and they want the URLs that they cite to refer to domains that aren't known as spam domains.</p>
         

http://www.spamnation.info/blog/archives/2009/08/spammers-hacking.html