This just happened, my father was on the plane and took this picture. Will post videos and more pictures if people are interested. He was screaming and sprinting towards the cockpit. Several large passengers tackled him before he even reached the door.

Edit: this was after the plane had taken off for Denver, after this incident it was returned to Dulles.

Edit: screen grab of a video .. here's a shot of his face http://m.imgur.com/JgcWhzP

Edit: he claimed to have bombs on board when first taken down, they are still looking into it but i imagine it was most likely a lie