A Google Groups member recounts one of the worst Google AdWords experiences: finding out that there were fraudulent charges on his card due to a new campaign that was created and incurred over $2000 in false clicks.
It seems that this is becoming more of a trend lately, as other forum members can relate. Another forum member, for example, suffered nearly $3000 in fraudulent charges. Yet another person saw a $5200 charge. On a note closer to home, a close friend of mine saw charges of $9000 over a single 24-hour period -- until Google stepped in and discontinued the campaign.
The concern, obviously, is "how did they get in there? Are you clicking on links that are from phishing scams?" My thought is that these are more savvy users who are not, but somehow the accounts are being hacked regardless. Perhaps it's related to signing into a Google account from a public computer; perhaps it's related to signing in to a Google account on an unsecured WiFi connection. One doesn't really know at this point. (Update: Or perhaps it's related to Google providing the wrong account details to users when they log in, thereby making it easier for people to easily set up fraudulent campaigns!)
However, AdWordsPro assures those who have been impacted that they won't be charged for the fraudulent charges. You're also suggested to contact your bank and Google's AdWords team so that they can perform a thorough investigation.
Forum discussion continues at Google Groups.