I work in the world of politics, and I've yet to see one of these. I think this is because in this world, if you talk negatively about your old job, your old boss, or whatever, no one is going to hire you. You become a liability. This has probably led to some horrible things happening to good people, but they keep their heads down, say nothing, because they want to still be employable. I have a similar situation in which I could probably become a whistle-blower against my former employer, but I don't, because if I do my career is over.