Burning Bridges - A Bad Thing

I have seen a number of individuals write down bad things about current or previous acquaintances or employers. This is a bad thing, mainly for the person posting the comment. If you call someone nasty names what will prospective employers think you are going to say about them? Will they take the chance that you won't say something similar about them? I have seen some absolute howlers festering for decades out on the internet so prefer to follow this advice: "Never type when angry or drunk" coupled with "if you can't say something nice, say nothing". If you write something in a public forum be certain you will be happy if it is read by your partner, priest, parents and colleagues.