"Quantity has a quality all its own."
As "social networking" merely now approaches over-hyped status, already we're warned of spam -- or rather, SNAM ("Social Network Spam"): Members of your networks, once, twice, or more removed, use the connection to market to you.
It's like CutCo or Tupperware, but somehow worse in the way that spam is somehow worse than unwanted phone calls. You can screen the phone, and you just don't get as many of them -- it costs too much.
But worse yet, it subverts something that could be of terrific value -- that, indeed, we're going to desperately need in a virtual future. Which doesn't mean we're going to slow our progress toward that future, of course: It will merely look quite different from the way it could.
A reaction is coming. As the barriers between people come down, and in absence of social controls on action, we are bound to become more closed than before.
I don't know exactly what form this reaction will take, but I have a dark and abiding fear that religion will be involved.