There are so many click fraud activitis in the Google Adsense players. Google has never disclosured any information about how to identify them. Adn also call it invalid clicks instead of click fraud.
An independent expert,(a professor at NYU, Dr. Alexander Tuzhilin, produced a 47-page report.
He mentioned ten sources of invalid clicks. If you are a newbie of Google Adsense player, it is good for you to understand which are not permited to do.
1. individuals deploying automated clicking programs or software applications (called bots) specifically designed to click on ads
2. an individual employing low-cost workers or incentivizing others to click on the advertising links
3. publishers manually clicking on the ads on their pages
4. publishers manipulating web pages in such a way that user interactions with the web site result in inadvertent clicks
5. publishers subscribing to paid traffic websites that artificially bring extra traffic to the site, including extra clicking on the ads
6. advertisers manually clicking on the ads of their competitors
7. publishers being sabotaged by their competitors or other ill-wishers
8. various types of unintentional clicks, such as doubleclicks or customers getting confused and unintentionally clicking on the ad without a malicious intent.
9. technical problems, system implementation errors and coordination activities between Google.com and its affiliates resulting in double-counting errors
10. multiple accounts of AdSense publishers: some AdSense publishers illegally open “new” accounts under different names and using false identities; all the clicks originated from these illegal accounts are considered invalid.