a severe long-term illness. long-term patients are more likely to connect to a community in health 2.0 public sharing data for research completing patient-reported outcomes and aggregating the data for personal and scientific research disease specific communities for patients with rare conditions aggregate data on treatments, symptoms, and outcomes to improve their decision making ability and carry out scientific research such as observational trials all (medical professionals and public) criticism of the use of web 2.0 in health care hughes et al. (2009) argue there are four major tensions represented in the literature on health/medicine 2.0. these concern: the lack of clear definitions issues around the loss of control over information that doctors perceive safety and the dangers of inaccurate information issues of ownership and privacy several criticisms have been raised about the use of web 2.0 in health care. firstly, google has limitations as a diagnostic tool for medical doctors (mds), as it may be effective only for conditions with unique symptoms and signs that can easily be used as search term. studies of its accuracy have returned varying results, and this remains in dispute. secondly, long-held concerns exist about the effects of patients obtaining information online, such as the idea that patients may delay seeking medical advice or accidentally reveal private medical data. finally, concerns exist about the quality of user-generated content leading to misinformation, such as perpetuating the discredited claim that the mmr vaccine may cause autism. in contrast, a 2004 study of a british epilepsy online support group suggested that only 6% of information was factually wrong. in a 2007 pew research center survey of americans, only 3% reported that online advice had caused them serious harm, while nearly one-third reported that they or their acquaintances had been helped by online health advice.