In this case the axis of evil happens to reside with Facebook/MySpace:
You have four friends called Bruce and invite the wrong one to the 'secret' party you have planned (why do all male friends have profile pictures of themselves dressed in superman costumes - yes really!). Cue 'secret' party becoming Halloween free-for-all.
The hot one night stand
Over a decade ago and through Lambrini-goggles, you search for him although there are three ways you could spell his name. He had blond hair, right, maybe dirty blond, it could have been brown. A good half hour is wasted. IF you do eventually find him, he is certainly not as you remember him and consider booking self-esteem classes.
The first love re-run
First love is intoxicating, too overwhelming with raging hormones to back up every love-fuelled sigh. First love was real and felt it would last forever or you would die. He is the ex you don't bump into at your local supermarket is somehow thrown in your face with a "Hi, how are you doing", "Your photos look great, you haven't changed" and "Do you get back to any of the local hangouts"?.
The ex-boyfriend's new (how young>?!) girlfriend
All of sudden updates include how much he loves his new bit of fluff, how lucky he is to have met her plus unnecessary photos of surprise weekends away *vomit*. You can't help but compare yourself to someone who wears a hell of a lot of pink and sequins and has to prefix every sentence with 'cute'.
One minute you're reminiscing on old times, with him saying he wished he were more mature when we met, to "do you remember that night we had sex six times during a rainstorm" to "I can remember what you taste like, what you feel like". Yes, even after five years of separation. Instant message sex has taken over from phone sex... Yet there is still an awkward silence after ejaculation.
Do you de-friend the ex only to regret that twenty minutes later you can't reassuringly check his status is "feel like shit" or be upset when all his photo albums are now called "party!!!!" or find that his wall is plastered with girls saying how funny he is (he isn't that funny)? Or keep him as a friend but revoke all permissions on your photos, status updates and heart?
Apologies if this makes me sound bitter, I'm not, my tongue is firmly in cheek. Facebook is a necessary evil in my life and without it I couldn't stay in contact with so many friends, especially those that have moved out of the comfort zone that is (for me) within the M25.