What's the worst thing that could happen to Google?
asheniam: How about click fraud getting wildly out of control? Google's profit is based solely off of online advertising.  Click fraud is a never ending battle to undermine that business and Google has teams of phds hard at work to understand what is click fraud and what is not.  Now if click fraud reached a point where advertisers can't trust the pay per click model, Google's revenues go poof.