Not everyone who makes a couple YouTube videos becomes an international pop sensation. But Justin Bieber did, seemingly overnight. While some folks may still ask who he is, there is a ridiculous, dare we say dangerous following for the Canadian teen star - and it's not exclusive to pre-teen girls. Here is a sampling of some of the craziest things that Bieber super fans have done. From knocking down his mother in an airport to paying a ludicrous sum for his water bottle, these fans don't mess around.