This video demonstrates a lot of the problems I saw running AdSense on USSM.
I have talked to Google about the “multiple advertisers with the same product” problem, and never got a good response from them.
One of the biggest problems with Google, and eBay and whoever, is that they have to weigh things like “rabidly persuing fraud” against “that fraud makes us money and we’re perceived as pretty good.”
Both could, if they really wanted to, dedicate the kind of resources required to dramatically reduce the fraud and misrepresentation they face. But the inclination to call it “good enough” when there’s a double cost to further action in resources and lost revenue must be almost irresistable.