Maybe not mainstream but one aspect of the advent of the whole social media/internet revolution is that old risk of people being rational as individuals but irrational when part of a mob. As we found with the Raoul Moat case, there is no opinion too offensive that several thousand others aren't prepared to claim to share it... As Harper Lee put it in To Kill A Mockingbird
"A mob's always made up of people, no matter what. Mr. Cunningham was part of a mob last night, but he was still a man. Every mob in every little Southern town is always made up of people you know--doesn't say much for them, does it?