The best question I can ask at this point is: what sort of monster have we created? We've created an interface where users are no longer accountable for their actions - after all, picture-wise, anything shy of pornography is pretty much allowed to be posted.
Let me put it in anecdotal perspective for you - when I was leaving High School, my teachers warned me that we would be leaving the safety blanket of a public school system and going into a private one. They were absolutely right - the real world is a cold place, but that's a lesson that everyone must learn of their own accord to grow up. Social networking sites are fostering the "safety blanket" once more - the reality of the social network is a perceived one, one that you create. The people you interact with are all people you know and trust, for the most part, unpleasantries can be avoided with some clicks of the mouse, and you never have to leave your house to do any of it.
It seems that people have forgotten what it's like to have to call someone up to ask them what they're doing that weekend to then arrange something - sure, it's not as easy as sending out a text message with multiple recipients, or sending out a Facebook event, but it's the way things work in the real world. Also, Facebook fosters what has become infamous as "Facebook stalking", or reading up on friends' conversations to find out what others are doing indirectly. While I enjoy reading on my news feed the events that my friends have been to, it seems almost like "Big Brother" to allow me to check back-and-forth conversations between two people.
Now, to my last point, which will probably make me less popular, but has to be said. One thing I always find amazing while reading through conversations on Myspace and Facebook is the absolute lack of any writing ability. Now, I'm not demanding sophisticated prose out of pre-pubescent teens with only one thing on their mind, but it would be nice to be able to read a complete sentence here and there, rather than the plethora of mistakes that can be found commonly written throughout. It just seems like the more people are expected to write to one another, the less capable they seem of stringing out complete, coherent thoughts - but that argument is about the American school system in particular and should be left for another day.
My overwhelming concern is what will happen to the people who spend hours on end attached to their social networking experience, but never grow as people. They will be making up the brunt of our workforce in the next 5-10 years or so, those who think they are getting a full experience when they are being cheated of what makes human interactions so special. Let's face it, while chatting with friends through Facebook is not that big of a deal, matters of romance and personal quarrels should done face to face, or at least over the telephone.
To conclude what is already shaping up to be my longest article ever - I want to make one point abundantly clear. Social networks are a very interesting proposition, bringing people together for the sole purpose of interacting. However, much like other immersive technologies (i.e. video games, movies, TV), it's important that interactions are still occurring in the real world more than they are through the internet.