http://www.ama-assn.org/ama/pub/category/1905.html

The Internet has permitted physicians, other health care professionals, patients, and other consumers to quickly access medical information in unprecedented volume. For those seeking easy ways to identify high-quality, reliable information, some Web sites and organizations have provided rating systems to evaluate quality of information on the Internet.Among Internet users who seek medical information, personal privacy was ranked as their most important concern. A recent study found that while many Internet health information sites provide privacy policies, most do not follow them. More than nearly any other type of information provided via the Web, medical Web sites must adhere to strict personal privacy codes to prevent individuals' personal medical information, including patterns of use and interests, from involuntarily entering the hands of marketers, employers, and insurers.