potentialgeek - 6:29 pm on Nov 10, 2011 (gmt 0)

There are certain conventions in ad placement, which you see on most major websites, e.g., leaderboards, 300x250 top right. I doubt Google would penalize those sites. It's more likely targeting the aggressive Adsense sites, e.g., two ad blocks stacked at the top of pages before content. They are usually good signals of bad quality sites (Made for Adsense).