Someone has started using this attack against my sites. It is quite effective at killing my organic revenue from Google Web Search... hopefully Google will close this one up fast. The way it works is that the attacker does a brute force DOS on the web server (leaving connections open and swamping the server socket on port 80) while googlebot is crawling the site. Googlebot marks nearly all the pages as 404 or 500 errors in webmaster tools. Then Google pulls all the failed pages out of the search results. I know. I know... How do they know when googlebot is crawling my site? This only works if it happens while googlebot is crawling the site. They monitor my URLs in the google cache and as soon as one updates a timestamp they know googlebot is on the site. It took me forever to connect the dots that the DOS attacks that only last about 1-2 hours every 2-3 weeks only impact organic traffic from google... I should have caught that sooner, but heck... I didn't expect google to leave huge gaping flaws like this open for exploitation. The effect is 5+ days of totally crippled organic traffic from Google. I don't know what keywords they are targetting but I am guessing that when I fall out of the SERPs someone else is moving up by default. Then they just repeat as needed until they get to where they want to be.