Over the past decade, the Internet has become a major source of public health information. The web does more than just provide information; it is also a tool for prevention and health promotion, offering online advice that may come from professionals as well as from industry. One of the major challenges is identifying the source of the information. For example, certain forums are exploited by participants who take advantage of anonymity—and the absence of real moderators—to advance hidden agendas. Nevertheless, the tool remains irreplaceable and extremely useful, provided it is approached with caution and a sense of perspective.