"The concept of friendship has enjoyed a renewed prominence in the vocabulary of the new digital social networks that have emerged in the last few years. The concept is one of the noblest achievements of human culture. It is in and through our friendships that we grow and develop as humans. For this reason, true friendship has always been seen as one of the greatest goods any human person can experience. We should be careful, therefore, never to trivialize the concept or the experience of friendship. It would be sad if our desire to sustain and develop on-line friendships were to be at the cost of our availability to engage with our families, our neighbours and those we meet in the daily reality of our places of work, education and recreation. If the desire for virtual connectedness becomes obsessive, it may in fact function to isolate individuals from real social interaction while also disrupting the patterns of rest, silence and reflection that are necessary for healthy human development."
At somegreybloke.com, though often crude and at times blasphemous, there is a clever critique of some of these dangers in the use of facebook.