MIT professor Sherry Turkle writes in her new book, Alone Together: “A behaviour that has become typical may still express the problems that once caused us to see it as pathological.”
She explains that people are become isolated from reality due to such social networking sites because technology is dominating our lives and making us "less human".
Under the illusion of allowing us to communicate better, technology is actually isolating us from real human interactions in a cyber-reality that is a poor imitation of the real world, she suggests.

I have two twitter accounts but rarely use it and only have one follower.

So I guess I have dodged the bullet on that.

CIA,FBI, MI6, NSA,WI?

just dont go past any grassy knolls

This is the nearest I come to any Social Networking site - although posting here is probably grounds for insanity

Given that I've stopped using FB for three years now, does that make me sane?

No.

You're not cured, you will be forever labelled "a recovering addict".

I make no appologies for using Facebook.
I use it because it's much easier to stay in touch with my friends when I'm offshore. Phone calls aren't an option as there are a lot of people wanting to use very few phone lines.
I use it much less when I'm at home.