Well for example with the rage party regarding Trump. I knew all the political opinions of my friends that have lost their minds over that (so to speak). I'm socially liberal, so their political
ideas mostly never bothered me (even when I disagree with them). Their behavior on the other hand, is grotesque. They've become what they proclaimed to dislike.
Almost all people behave differently under different social circumstances and pressures. Facebook seems to bring out - unleash - the worst in some very nice people. My observation is, as one would expect, they justify the bad behavior by proclaiming that the venom spewing is justified by the nature of the opponents they're attempting to counter. Means justified by the end goal.
It's said that online anonymity + forum = asshole behavior. I've come to wonder if enough time being acclimated to a public social network like Facebook, doesn't degrade the social niceties and manners that used to exist among friends in the early days of MySpace and Facebook.