While there is some overreaction, it has been documented that teachers and corrections officers have been asked to provide access to their Facebook account as a condition of employment.
No big deal, right? Well, I'd argue that it is --- I know at least a dozen teachers and a few policemen. If those acquaintances are my "friends", the person doing the background snooping will have access to things relating to me that I was intending to share only with friends.