How Benefitial or Damaging can Internet be?

During our languages classes, a classmate of mine talked about Bulimia and Anorexia, and about an Internet website which was created by teenagers who are suffering from these diseases. They use this website to share their daily experiences with the these illnesses. This page is used as a sort of catharsis. But is this good or bad? I cannot truly say. But I beleive that Internet has a lot of good benefits for people, but also can be used to make harm to others. In this case, there is anything beneficial for these girls who have bulimia or anorexia because all they do is to talk about how skin they are, how much exercise they have done, how much water they have drunk. And the worst thing is the photos they have published. They are really shocking because you can see their naked bodys so thin that scares you. And my classmate said that if you tried to say to them that they were ill and they needed some medical treatment, they will not allow you to interact with them.
These girls need instant help. But they say that being bulimic or anorexic is a personal choice and a way of living. They are completely blind. In this case, other girls who see this kind of website can feel the innert compulsion to look the same and follow this trend, or just ignore it. Nevertheless, this kind of websites should be controlled by somebody. Otherwise, the can do a lot of harm to the minds of innocent teenagers who use Internet to be connected to the world.