Violent movements, uncontrollable excitement, dementia. These are just a few symptoms of rabies, but they also describe the effects of Bieber Fever, a mysterious psychosis caused by Justin Bieber that is affecting adolescent girls worldwide. From Long Island to Australia, anywhere the Canadian pop star goes, stampeding tweenage fans follow. Just yesterday, a swarm of fans in New Zealand tackled Bieber's mom while trying to cop a feel of the 16-year-old. And while Justin Bieber may have set a new standard for turning ordinary girls into blood-hungry Wildebeests, he's hardly the first boy pop star to cause a ruckus, as you'll see in our History of When Boy Bands Cause Violence.