I was just thinking about this click fraud issue, since anyone who advertises in a “content network” has seen bogus clicks including myself. That’s why I have opted out of all of “content networks”.
However I don’t think this issue is unsolvable especially for Google.
Google should require that all adSense providers use Google Analytics on all there pages within there domain. And then give access to the analytics of the providers of click to advertisers. Heck they could probably identify all the bogus clicks with analysis of the data collected.
Secondly they need to add “Locality” to adSense if I specified “St. Louis” in my campaign then I certainly don’t want clicks from Korea. This alone would probably reduce click fraud to nearly nothing.