Due to problems related to artificially Clicks, Google AdSense has been criticized by some companies have a website optimized to appear in the top of the top search result by the number of very large Clicks do not have to be the company’s opponents used to increase the cost of their ads. That is why it without the Vietnam AdSense members have been blocked by Google, although many of them said that they fully play by the rules of Google AdSense.
To combat fake clicking, who posted ads can choose to use certain programs to detect click. This form of a program to identify visitors. They allow displays detailed information about access to and click on the AdSense ads. Those who post ads can use this information to determine whether you are a true victim of clicking virtual or not. There are many scenarios (script) format was sold but also has a program open source has the same function is AdLogger.
Google also been criticized for allowing AdWords advertisers brand abuse. In 2004, Google started allowing advertisers to bid on any search for any arts, including the brand names of the competitors.
How Google’s payment for participants in the program posted ads also been criticized a lot. According to the regulation of Google, the ads appear only be paid once gom sufficient amount of at least U.S. $ 100. While for those who participate do not have the size to get the 100 Dollars they take a very long time, even as every year.

Read TOS Google adsense: https://www.google.com/adsense/policies