I have a site that get's roughly 7,000 - 10,000 page views per day right now. Starting around 1 AM on 7/1/12 I noticed the CTR was rising dramatically. These clicks would be credited then de-credited soon after. So, they were obviously fraudulent clicks. The next day I had about 200 clicks with about 100 of them being fraudulent. It's about 3 - 8 clicks per hour evenly dispersed for each of the three ads 24 hours a day. This leads me to believe that it's some sort of Adsense click bot. Also, I removed the ads last evening then put them back up around 3AM and the invalid clicks started within 10 minutes.
I signed up for statcounter.com to analyze the exit links on the Adsense. Then I conditionally blocked ads for the IP address of the person / bot I suspected doing this. But, I think that the bot has several proxies to choose from and can refresh IP addresses.
I've notified Google through the invalid click form / email 4 times over the past two days in order to let them know I'm aware of the situation and am working on a solution. I've also temporally removed all ads on that site.
How can I block a bot like this? Thank you.