I'll also add that what constitutes positioning an ad for accidental clicks vs positioning it for maximum viewer visibility is a very fine line sometimes and the very fact that Google constantly fidgets with ad positioning inside their own units and changes up the look of ads at their whim is tantamount to straddling the very line they brutally enforce with webmasters. Taking the hot spot of an ad and moving it from the center of a 970 pixel wide space to the far left is HUGE where the path of the reader's eye is concerned. Even on an editorial site, this kind of move can result in the user going right by without even noticing the ad. Or it could result in the user walking right into it depending on the situation. The whole point of these "enhancements" is to make the ads more compelling to viewers. Google wants the clicks and if mucking with the layout serves that purpose, I'm sure they have no problem continuing to take back revenue that they determine was an "accidental" click, even if their own mucking with the layout was the cause in the first place.