Funny how we've been discussing this over the years and each time it is brought up there are always a "large" group that blow it off. I'm waiting for them to chime in here. I've been following this stuff now for a few years and it has been a major revelation! ;)
Here are just a "few" past topics. And then, I've just provided a link to incrediBILL's WebmasterWorld Profile as it would take pages upon pages to list all the topics he's started and has participated in regarding these matters and other security related challenges. Grab a "pot of coffee", click the print button and get ready. :)
DNS Recursion - Open DNS Servers
The new open relay problem. Are you addressing this?
2006-03-14 - [webmasterworld.com...]
DNS servers make light work for hackers
2006-03-24 - [webmasterworld.com...]
DNS Cache Poisoning
Redirecting web traffic through cache poisoning.
2006-04-10 - [webmasterworld.com...]
Is your hard earned and paid traffic being redirected?
2006-04-12 - [webmasterworld.com...]
The Saboteurs Of Search - Part I
Google Bowling - 7 Ways Your Site Can Be Sabotaged
2007-07-01 - [webmasterworld.com...]
The Saboteurs of Search - Part II (one year later)
2008-06-20 - [webmasterworld.com...]
incrediBILL's WebmasterWorld Profile
2008-07-31 - [webmasterworld.com...]