“This consumer complaint raises a number of concerns about Facebook’s privacy policies and practices,” the committee leaders wrote in the letter. “Facebook’s systems lack transparency as to how they are able to gather personal information and synthesize that information into suggestions of relevant medical condition support groups. Labeling these groups as closed or anonymous potentially misled Facebook users into joining these groups and revealing more personal information than they otherwise would have. And Facebook may have failed to properly notify group members that their personal health information may have been accessed by health insurance companies and online bullies, among others.”
Facebook misled users who discussed their medical conditions in "closed" groups that they believed to be private and anonymous. But Facebook says users who shared information in these groups should have understood that the social network "is not an anonymous platform."