Here is another perspective from my amazingly talented SIL over in the Wine-Dark Sea combox (Yes, Husband has not one, not two, but three red headed sisters!) I am posting it in it's entirety here so you don't have to scroll through to find it but do go read Melanie's thoughtful post on the the subject that has been on our minds lately:
I have two main problems with social networking sites, which is why I choose not to use them. My husband uses both Facebook and Twitter, so I've gotten to see how both work--this isn't a case of rejecting something without understanding it.
My first problem is similar to what Charlotte says above: why on earth would I want to be contacted out of the blue by people I "left behind" a long, long time ago? The people who are near and dear to me are people I already am in touch with; the others are faces scattered in memory, forever ten or twelve or eighteen to me. Granted, I moved a lot as a child, and don't remember the names or faces of most of my classmates; I also did not form many lifelong friendships in school, and can honestly not think of anyone I'd really be delighted to discover suddenly on the Internet. The reality is that most of us grow, change, and constantly become new people, and I'd find it terribly limiting to be in the virtual presence of people whose last memory of me was when I was an awkward fifteen-year-old or an immature college freshman. When you remain friends with someone, you grow together, experience maturity together, and the friendship is deeper and richer than it ever could have been in the past--but those people who remain in our past are often there for a reason.
The second reason I avoid social networking is because I can't help viewing it a little bit as a homeschooling mom. We're always trying to keep our kids from what some call "twaddle," useless busywork that occupies the time but not the mind, right? Now, I mean no disrespect for those who have found it possible to engage in deep, meaningful, philosophical exchanges on Facebook or on Twitter, but I know that such exchanges must come about in spite of, not because of, the format. The formats are geared toward quick, surface-level observations and sharings: what I did today, where I'm going this weekend, what my child said at lunch, etc. Now, there's nothing wrong with sharing these things if this is what you LIKE to do, and for those whose Facebook friends or Twitter followers are pretty much all immediate family and close, long-time friends I could see that this would, perhaps, be easier than calling each person individually to discuss daily events or weekend plans, etc. But for me, personally, to reveal this level of minute detail to people I haven't spoken to since the fifth grade, or to people who sign up to "follow" me because they once read something somewhere that I wrote, would be an exercise in "twaddle," that very thing I'm teaching my children to avoid.
Please note: I'm not saying that social networking = twaddle, or that there's nothing of value in it for those who did have lots of close high school or college friends with whom they had sadly lost touch and whom they are delighted to have in their lives again. But I can only look at this as an individual, and knowing myself, and my use of the Internet and my constant struggles to find balance between my real obligations and responsibilities and those interactions which take place online, I know that the last thing I need is the kind of format where several times a day one might see new messages or tweets or wall-writings from dozens of different people who don't live close enough to drop in, and who won't see me scrambling at the last minute to get dinner ready because I've spent too much time already on the computer for one day.
Now, how is sharing these small things online different from sharing them face to face, over coffee after Mass perhaps? To me, the difference is that when we are in a face to face, real time encounter with another human being we have a moment where we are truly present to them, and they are to us; we enter into their time and space, so to speak, and they enter into ours, and that moment of shared "now" becomes a memory for us both, and a chance to grow in our understanding of each other that goes far beyond the mere subject matter of the conversation. Online conversation can be wonderful for what it is, but ultimately it is limited; how often have arguments broken out over a misunderstanding in tone, or offense taken where none was meant? Face to face, a thousand different cues put us at our ease: smiles, eyebrow arches, twinkling eyes, friendly laughs, and a quick "I'm sorry!" if one unintentionally offends. None of that is possible in a message posted for dozens to read, and read by some long after it was written.
Does this mean that some kinds of online communication are inherently "bad" and others "good," as some have written? Not at all. I agree that any form can be used well or badly, with good intentions or wrong ones, for God's glory or for our own purposes. But again, speaking only for myself, the format of social networking with its quick messages and widespread reach would most likely be "bad" for me personally--and I really think that most critics of social networking have said as much, that our problems with it come from an understanding of who we are, and what sort of temptation this type of site could easily become for us.