No, this isn't a post of movies about THE Mob (which I think there are far too many of anyway). This is a post about what happens when mob mentality takes over and people allow themselves for whatever reason to be subsumed by a group. Now this was harder to put together than I first thought when I came up with the idea. There are plenty of Westerns with this theme- lynch mobs abound in the old west. And certainly many war movies are prime examples of 'group think'. So after racking my brain, here is what I finally came up with.
Lord of the Flies---perhaps the quintessential story of what happens when mob mentality takes over. All the more frightening as the perpetrators and victims are a group of priveleged, well raised children.
12 Angry Men---a Henry Fonda classic about the jury in a murder case trying to reach a decision.
The Ox-bow Incident---again with Henry, this movie easily makes it onto my top 10 favorite Westerns. This works well on so many levels but it works best as a study of men being led by blind conviction to an idea
Hotel Rwanda---take generations of tribal hatred, a government openly soliciting murder, Peace Keeping forces hamstrung by their own mandate. Just in case this isnt enough, add a world community not particularly paying attention and you have the story of the horror that was Rwanda. Don Cheadle stars as one man who tries to take a stand against the genocide. We also have the excellent non-fiction Shake Hands With The Devil---the story of Canadian Lt. Gen.Romeo Dallaire and his command of the United Nations mission to Rwanda during the 1994 genocide.
Rod Serling often chose to examine what happens to people when put under pressure in a group. Check out any of The Twilight Zone--- we have lots!
If you ever come across the movies Rosewood, Fury (Spencer Tracy), 1984, or M, make sure you take the time to watch them. All are excellent examples of this theme.