You may hear people rage on about how an employer saw something on their Facebook page and they got reprimanded for it. How about courts allowing those you sue to look at "private" wall postings and bring them into court if they are relevant?
You may say: "Hey that's private! They can't do that!". You may be right in some instances, but the real problem is that people still believe they have any sort of privacy whatsoever when they post things online. Getting upset over it seems more ignorant than it does justified. Before you had Myspace, or Facebook, would you announce on a billboard that your boss was a jerk? Would you talk about company secrets on a billboard? This is literally what you are doing when you post on blogs, Facebook, and anywhere else online that others can see. Just because you have your Facebook set to private means very little. People hear stories about being hacked all the time, but think nothing of bringing private info to a public website? Think idiots!
If you want to tell people you can only sleep on the grouhttp://www.blogger.com/img/blank.gifnd in a sleeping bag, don't post pictures of yourself in deep sleep on a foam mattress. Lying online when you use your real name is never going to end well. If you have 100 friends I'll guarantee you that 1 of them isn't that stupid, and they aren't going to let you get away with it.
On to being an employee and trying to pull a fast one. Just because you are an attention whore and want people to think you are clever doesn't mean Facebook is the place you should go to prove you are screwing your company with a false injury claim. This doesn't make you clever. It makes you stupid. Take a look at some court rulings that people like you may have to deal with one day when you try to get away with faking injuries.