"Some of the Google AdSense ads have recently been served and tracked via DoubleClick. Here is a picture of me with my mouse over a Google AdSense ad from my personal blog. As you can see, the tracking URL is http://googleads.g.doubleclick.net/pagead/iclk?."

Personally i noticed this to indeed,

http://www.seroundtable.com/archives/018920.html

The sample link doesn't work