It is all about the lense through which you view life.
I can look at some pictures of my friends and yes, I do sometimes feel a little worm of jealousy (or is it envy? I can never remember) and if I am in a down mood I do have to go away and do something else. But as someone else said down thread, I realise that this is MY problem.
When I am in a good mood and feeling happy with myself, the exact same photo will not provoke a negative reaction.
The other thing that baffles me, apart from the all my friends want to rob me mentality, is that there is an immediate and obvious solution to feeling unhappy about Facebook - don't have an account. Or limit it to 20 or so close friends that you can trust not to be shallow and insecure twats who are motivated primarily by making you feel shit about your sad life.
And if you can't rustle up even a handful of people that make you feel good about yourself, time to admit there is a real problem and it has absolutely nothing whatsoever to do with the internet.
And if you can't do any of the above, why do you feel the next step is to come on threads like this and tell those of us who indulge in social networking that we are all 'twats' 'sad acts' 'insecure' and 'shallow' ???
These are probably rhetorical questions. I think I know the answer to all of them.