Microsoft filed a lawsuit against three people accusing them of breaching Microsoft's adCenter contract by running a click fraud scheme along with several companies and other, unnamed parties, asking for at least US$750,000 in damages. The lawsuit centers on a scheme to bilk competitors by clicking on their on-line ads, promoting auto insurance and World of Warcraft on-line game, Microsoft said in court filings. Typically a percentage of those clicks result in sales and cover the amount paid for the traffic. However in the instance of alleged click fraud, no sales were made and the victim companies lost money. This type of activity also hurts the performance of the ads and can push them down in rankings.

More info: Computerworld