Play by the rules, and report those that don’t. That would be my methods of attack. As a technical guy, I am well aware of screen scraping techniques. Some of the spamindexing techniques have become quite clever, to be quite honest.
The best way to defend is to get the Search Indices to work with us, and make them realize the negative impact that all of these BH’ers have on our revenue streams (including long-term SE survival and longevity), and the integrity of the Internet.
If we can accomlish this, we will accomplish 90 %. Definitely an up-hill battle from here on in.