Click fraud is a type of fraud that occurs on the Internet in pay-per-click (PPC) online advertising. In this type of advertising, the owners of websites that post the ads are paid based on how many site visitors click on the ads. Fraud occurs when a person, automated script, or computer program imitates a legitimate user of a web browser, clicking on such an ad without having an actual interest in the target of the ad's link. Click fraud is the subject of some controversy and increasing litigation due to the advertising networks being a key beneficiary of the fraud.