Zombies and Cannibalism in the News

According to this article, there have been at least eight instances of cannibalism and face-eating in the last couple of months. If bath salts are not to blame, then what is the factor at work? I have to agree with the author that this cannot be explained as merely marijuana. In the history of the world, there has been a great deal of marijuana usage without people biting off the faces of others. I am not conspiracy-minded by nature, but something strange is going on here. Mass hysteria?