My profuse apologies to everyone. It seems that Google is not in fact involved in any way with providing reverse DNS for the 204.8.136.0/21 IP address block. I was deceived into believing it was by some unusual trickey on the part of the spammer-controlled name servers ns1.saversagreeable.com and ns2.saversagreeable.com. You can see the clever deception toward the very end of the dig +trace listing I posted: http://pastebin.com/raw/VNwmgMHh It seems those clever rascal spammers tried to implicate Google's name servers, but it is only their's which are giving out the reverse DNS which suoorts their snowshoe spamming efforts in the 204.8.136.0/21 block. Sorry for my mistake everyone. I wasn't expecting quite this level or kind of reverse DNS delegation trickery. Regards, rfg