Click bombing is a practice people use for destroying other people’s web sites income coming from AdSense. Google Adsense has an official “Invalid Clicks Contact Form” that you can use for reporting any unusual account activity. If you are using WordPress then one more preventive method is to use CbProtect, a free WordPress plugin for protecting your Adsense Account from Malicious Clicks.
CbProtect is an easy and user friendly WordPress plugin available free of cost. It simply disables ads showing on your site when the click count reaches to a specified number from the same IP.
Install and activate CbProtect. Visit WordPress Admin Area Dashboard -> Plugins ->CbProtect and set the configuration settings.