Facebook signup begins with you providing information about yourself - likes, dislikes, etc. I would say that this encourages narcissistic behavior (vanity).
Surely people can pursue education for selfish reasons. But, believe it or not, some people choose an educational path to acquire a career that may positively impact others.
There are plenty of other Web 2.0 tools designed with greater advantages than Facebook. One is Edmodo, Ning is another.
I find it hard to believe that trying to acquire many "friends", for the sake of having your numbers increase, is not tied to narcissism. Or, how about posting and trying to see how many people you can get to "like" your comment? I feel that there are many other narcissistic features linked to Facebook.
It may be a tool that people choose to use on personal time, but it does not have a place in the classroom where we are encouraging students to think about others, and not always self. There are other ways for us to nurture the social growth of students.
