Is there anything wrong with Facebook and Social Media?

I would really like your input about Facebook. Are you on Facebook, myspace, twitter, etc? How much time do you spend on those activities? Here is my dilemna. First, of all most of these sites people are extremely focused on self and share that with everyone else. Secondly, as a therapist I am seeing an explosion of Facebook affairs. People getting connected with their highschool sweethearts again and leaving their families. Now on the flip side. I enjoy staying connected with my nieces who live in another state. Also, friends that live in other states. I just think there is a danger with Facebook. Also, do you use Facebook, etc. to share Christ with others? I think as with anything we need to watch how we spend our time and does it glorify God. I'm interested to hear what you think.