In Sundays Washington Post, the article 'Click Fraud' Threatens Foundation of Web Ads was published.

The article describes how Jackie Parks, a disabled stay-at-home mom in Iowa spends hours each day clicking Google AdWords ads for- 1/2 a penny (!)a click. She says she makes 300.00 a year doing this.

Jackie gets a daily email list of all the sites she needs to visit and what ads to click. These organized ring of clickers are sometimes called "paid to read" networks. Simply by running a simple Google search you will find lots of these paid-to-click service site's looking to recruit.

Google AdSense has long been a target for fraud.
Scams range from bots that automate the clicking process, phishing email campaigns that incite email recipients to visit to phony web pages and click on ads and the latest- networks of site owners trading clicks. India has become a real hot spot for commercialized paid-to-read "businesses". With its huge pool of cheap labour and a with a country with one of the highest broadband user per capita it has become a haven for these types of schemes.

Google advertiser's have long been frustrated by ad fraud and the inability to track and document click fraud. Google will reimburse advertisers money of they can document that fraud has taken place.
Articles like this in mainstream news do little to allay fears of potential scams.

One way to avoid be a victim of AdSense abuse is to turn to a professional pay-per-click manager or search engine marketing professional to help you spot fraudulent patterns or manage your campaign and tracking.