Facebook - handle with care

Before I get into posting research about the wedding videos and invitations (which is reaaaally boring) there is this one idea I had in my head for a while now.

Facebook, the social network giant. Freedom of speech, freedom of use.. but really?

Every teacher and every person to ever work for a serious company would tell me the same: watch what you post and what you get involved with while using the social networks.
There's been plenty of stories of people who lost their jobs due to reckless use of facebook: the one I can recall right now is some girl who while changing jobs decided to boast about it too soon.

Well OK, this is plain stupid. You don't tell the whole wide world about these things before they actually happen, especially if you're moving to a rival enterprise.

What about social life then?
I heard that wicked party pictures and excessive usage of the 'less productive applications (come on, we all know what I mean)" can have a bad impact during the trial period. That is understandable of course. Nobody would hire a binging party animal who boasts to the whole virtual world how hungover they were during their last shift.
On the other hand I know plenty of people who brainwashed with marketing and self-advertising methods make their facebook page like an interactive CV. Not a single song, no up-coming trailers, no witty comments about weather (oh come on, we all do that!). Every single status update is a deep reflection on how a random event in their life benefited their career (which most likely they havent started yet). "I just went hiking with 5 friends. We came back alive, I lead the flock, cause I go hiking often. Love my team-work and leadership abilities. I am sure every multimillionaire business executive should be a hiker"

Is this normal?
Like every other human being on the planet, I *am* shallow. I love good feedback and attention so of course I will post every good piece of artwork I produce. But hey- this is a social network website. I'm a casual guy - I do work to pay the rent, I have plenty of work at the university but at the same time - I drink, I party, I am a terrible smoker. I make mistakes, I love to waste my time watching soap operas and I play Angrybirds on the bus (instead of reading "succesful in 30 days" kind of books). I'm human.
Should I hide all these facts and present some warped artificial version of myself only to secure a job opportunity? Do the serious companies expect their potential grunts to be machines who after their 9-to-5 go back home and instead of  living their after-hours keep the tie on?

Maybe I look at this in a non-professional manner. But trying to image a potential employee for my non-existent company - if the interviewee answers that their past-time activity is personal development, self-promotion and forbes.com, well... I'd still hire you based on the vacancy requirements but  hey - you're a freak.

P.