We all know by now that posting embarrassing pictures of ourselves on Facebook is not wise. Potential employers, future bosses, etc. can all find a way of seeing these if they really put their minds to it. One mishap- just one picture of drunken sloppyness, and we could lose many opportunities.
But in addition to this, I think many members on Facebook must take into account what groups they join, and what pages they become fans of. It may not always be the first thing we think of when we are trying to cleanse our profiles for employment reasons, but it is just as significant.
I highly doubt that an employer will appreciate a potential prospect who is a member of "I can bullshit thru anything" or is a fan of "I hate stupid bitches," or "Mom, we're smoking weed and having sex...not hanging out". All of these are real pages on Facebook- I looked at my cousin's profile and found them. He has plenty of other "inappropriate" ones too. The next time I see him, I might have to tell him get rid of these.
This all shows that even though these groups and pages are funny, just like those photos of you doing a keg stand, it just may cost you a whole lot later on.