In most cases, Web 2.0 health sites are positive step forward. But as with all user-generated content, there is the chance of misinformation:

On the internet, as the old saying goes, nobody knows you are a dog””or an idiot, notes Dan Keldsen of AIIM, a non-profit association based in Silver Spring, Maryland, which helps companies manage digital information. And too much health information can confuse people, says Monique Levy of Jupiter. But a survey by the Pew Internet & American Life Project in Washington, DC, suggests that although user-generated information offers consumers more health options, the upside outweighs the risk, says Pew’s Susannah Fox. Nearly one-third of the 100m Americans who have looked for health information online say that they or people they know have been significantly helped by what they found. In contrast, only 3% reported that online advice had caused serious harm.