One click too many can get your Adsense account banned for fraud. Invalid clicks are the main reason for a ban, as they violate Google's Terms of Service. You may only find out when you get an email or you cannot login to your Adsense account. Disputing this violation with Google can take some time, but if you are patient and follow these steps they may reinstate the account : Step 1 : Write to Google to explain that you have not violated their Terms of Service. Keep your tone pleasant and offer to provide evidence to show that any clicks on your site are legitimate. Grovel a bit if necessary and ask for a human review. Google will ask you for information before they consider your appeal. Step 2 Provide the information requested by Google about your publisher ID, website URL, the source of your traffic, your site's audience and any other relevant information. This will show Google that you are serious about your appeal. Step 3 Collect evidence of the reasons for the suspicious clicks that have led to the Adsense ban. Sometimes a surge in traffic can look suspicious, but if one of your pages has featured on Digg that is a possible explanation. Server logs can also show whether traffic is valid, so keep a backup of these. Step 4 Continue to write to Google every couple of days. Ask for updates on the review process and include more evidence which will support you case for having Google lift the ban on your Adsense account. Step 5 Wait for a decision. It may take up to 30 days to get a decision on the Adsense ban. If you have provided enough evidence of your innocence, once the decision is made you will get a letter from Google that your appeal has been successful. __________________
Actually, Step 1 should be to re-read the Terms of Service and actually be sure you aren't in violation. Many many people who post here about their accounts being banned for "no reason" are actually violating the terms. Often it's because of copied or adult content, linking to illegal movie streams or game downloads, lack of privacy policy, use of traffic exchanges, or the like. Google is not stupid, and there is no point asking for a review of a site that is not actually in compliance.