There is no privacy in a busy place. Facebook is a busy, bustling place. The less you share, the more value you lose from sites like Facebook. It only works BECAUSE people share information about themselves. If you want privacy and want to keep your social circle small, go create a private network on Ning and encourage your friends to join you there.
My recent post Today’s #ff love for hearts of gold: @that_angela, @lyncadence and @donnamct

Great points Emily! Our behaviours haven't changed, just the mechanics through which we achieve them have changed because of technology. "The more things change, the more they stay the same" couldn't be more true in how people interact in the social web.