Keyword targeting with irrelevant content - Against TOS

We could see many websites with content which are irrelevant to the ads displayed by Google Adsense for that particular site. It's not because Google adsense have done their job wrong, its again one of the game played by the webmaster for greater earnings. The webmaster could target ads to high paying keywords even though the ads which ought to be displayed are low paying. The publisher could produce some clicks to his ads even though the ads were not related to the content. This could produce more earnings than with the usual keywords he could have used relating to his content. His content would be liked by large number of visitors but could be of very low paying ads which could show up for that content. This tactics is now a greater problem which could produce unwanted clicks for the advertisers. This results in a failure in Google Adsense. So Adsense have started taking appropriate measures against such methods employed by some publishers. My friend was once warned and was asked to make appropriate changes to his site if he was interested in Google Adsense anymore.