I found this story on businessweek.com. It seems businesses are really trying to take it to the next level to prevent click fraud. Understandable. I just hope that they dont take it to far as someone suggested in the article as to limiting sites with a certain amount of visitors. I think thats one of the great thing about adsense is that you can be a very small site and still make some kind of income. At least to cover hosting cost.
Here is a link to the article.
http://www.businessweek.com/magazine/content/06_40/b4003001.htm?campaign_id=ds5
Here is a link to the article.
http://www.businessweek.com/magazine/content/06_40/b4003001.htm?campaign_id=ds5