In the Dutch news there was an item about the so-called 'pro-ana sites'. Websites that connect girls with anorexia. The pro-ana movement believes their behaviour is not disease but a lifestyle. 25% of the anorexia girls/women under medical treatment visit the pro-ana sites, often weblogs. The three girls who were interviewed in the news explained that they were really attracted by the sites and the tips they can get on the sites eg. about 'how to avoid eating', 'how to cheat your parents'. One of them did not identify with the site during her first visit because the girls were too skinny. But later she was attracted to come back. Another girl could spend 3 hours per day on the websites. They feel the sites are dangerous because of the enormous appeal to the anorexia girls and the way the girls on the websites stimulate eachother with tips to give in to their obsession to avoid food, on a downward journey. You can still watch the interview with 3 girls in Dutch here.
Though I originally did not think of patient communities as communities of practice because they do not have a professional practice, I currently think you might think of them as one. Look at the way of living of the pro-ana members and they way they behave: a very strong practice. You can see that the websites give enormous power to the pro-ana communities. At the same time, it is an enormous reminder that communities of practice are not something good and to be promoted everywhere. It depends on the practices, the innovation etc. whether a communities can be labelled as good and should be encouraged or discouraged. The pro-ana community seems to do well in helping new entrants to get up to the task. However, the practice is horrible (no photos to match this blogpost...!)