Anyone have a patch to INN for scanning posting-hosts for open proxies?

[Joe St Sauver]

I was wondering if anyone has a patch to INN for scanning posting-host 
headers for open proxies via one of the various dnsbl's that are out there? 
(blitzed, monkeys.com, osirusoft, etc.) The goal would be dropping traffic 
posted via open proxies in real time, thereby eliminating the need to shun 
whole servers when open proxies end up getting exploited. (And based on what
I'm seeing at http://www.monkeys.com/security/notices/proxies/20020809/
it looks like there really are a *lot* of them out there). 

I am thinking that you could do it via a modification to Cleanfeed,
but I wanted to make sure that I wasn't reinventing the wheel 
here...

Thanks,

Joe