All of a sudden, people are able to share the most personal of news with a mass of people - all at once - many of whom barely know you, and who, quite frankly, are rather uninvolved in your everyday life. Your closest friends can feel cheated (and I have felt this way myself) that you have shared this news with everyone equally. There is no longer a sense of "who do I tell first?" when it comes to major (but personal) news in our lives. All are given equal access - and thus, equal status - in our circle of friends and acquaintances.
For this reason (and others), I've been selective about joining social networks. I'm not on Linked In. I'm not on Twitter. Perhaps it's to my own demise. But for now, this is the best reasoning I can come up with. If you have thoughts about all of this, please let me know. I'd love to hear from you.