Personally I've gotta go with the common sense rule on this one. My FB account has very few friends, who are actually real friends and two of them are people I work with.

My thought is this; if I wouldn't say it at work in front a customer or my owner then it isn't going on FB. Lately some of political views have started to end up on my wall as my frustration with "the man" grows. I've kept it in check enough not to piss anyone off.

It's the internet though. Once you put it out there, it will be forever and for anyone to use against you.