We learn all sorts of things about our friends though Facebook. In the past two months, I've heard about two friends' breakups, one friend's new boyfriend and the birth of a co-worker's baby -- all through my Facebook friends feed. But, according to Newsweek, some users are receiving a far more shocking status update, the subtext of which is: Your friend has an eating disorder.

She would "encourage others to post their pictures online and then harshly detail their 'problem areas'"

Controversial pro-anorexia (or pro-ana) Web sites, which encourage girls and women with eating disorders to swap tips on extreme weight loss and share "thinspiration" in the form of photos of emaciated models, have spread to the social networking site by way of member groups. Unlike typical pro-ana sites, where users post anonymously, these groups "link users' real-life profiles to their eating disorders," reports Newsweek. Of course, some create anonymous profiles for the purpose of participating in these Facebook groups -- but many use the same profile that connects them to their friends, family and co-workers. Just imagine the following showing up in your feed: "[Insert friend's name] joined the group 'Ana Boot Camp.'"

As the piece points out, Facebook allows for far more intimacy because group members are "able to see people's faces, friends and interests." Kate, a 20-year-old college student in Utah, told Newsweek: "Myspace was more focused on tips and tricks and when to exercise. [On Facebook], there's a lot of really close networking, so you add those people as friends and exchange phone numbers, and when you're having a hard day, you talk on the phone." She describes Facebook as "a lot more of a support group." Of course, most outside of the community fail to see it that way -- or, at least, as positively supportive.

Just as with anonymous pro-ana sites, there is the fear that these Facebook groups will push members further into the depths of their illness rather than toward recovery, and they have just as many opponents actively trying to infiltrate and shut them down. "Recently, they managed to shut down one notorious site as well as the Facebook account of its creator, a girl who would encourage others to post their pictures online and then harshly detail their 'problem areas,'" according to the article. Facebook employees also search for and delete groups that encourage self-harm. As a result, pro-ana groups have gone stealth: They have subtler titles and are often set to private so that they are unsearchable.

Still, some see the emergence of these groups in this semi-public sphere as a positive development. "Girls are concerned about other girls in their social group who they see toying with an eating disorder," says Marcia Herrin, the author of numerous books on disordered eating. "They may talk to them directly, they may talk to a school counselor, they may talk to the girls' parents."

Indeed. A girl could anonymously join a pro-ana site hidden at the edges of the Web without her friends or family ever catching on. But, because of the real-life link, joining one of these Facebook groups is a loud cry for help. A friend need only click over to your profile and take a look at your list of groups to become seriously concerned.

Only, it doesn't always happen that way. Rose, 17, joined several such groups hoping her friends would notice and "rescue" her -- they didn't. So, she says, she resorted to getting attention from "other sick people."