A recent article published in the American Journal of Infection Control  titled “Dissemination of health information through social networks: Twitter and antibiotics” [ link to abstract ] demonstrates how social networks, specifically Twitter, is being used to share health information on the web. In this case, Twitter was a great conduit to share health information, but the reliability of the information wasn’t so great. ArsTechnica has a good summary of the article here .
This article just highlights the idea that consumers need to be wary of trusting health information on the Internet. The Journal of Medical Internet Research (JMIR) has done some work in assessing the quality of health information on the Internet for several years. Here are just a few examples of articles on the topic:
The moral of the story is that for health information on the Internet, you should assess the quality the information, test the credibility of the source, and check the reliability (i.e., is this consistent with what other sources are saying).
 Scanfeld, Scanfeld, & Larson. (2010). Dissemination of health information through social networks: Twitter and antibiotics. American Journal of Infection Control, 38 (3), pp. 182-188.