Justin Bieber might be the first YouTube phenomenon to truly achieve real-world superstardom, at least among middle schoolers. Known to anyone above the age of 16 as an inexplicable Twitter trending topic every single day, the pint-size R&B heartthrob has captured the hearts of teenage girls everywhere with his G-rated videos about losing his first love and picking up a (suspiciously older) girl at a Laundromat. Bieber's popularity is such that he caused a riot at a Long Island, New York, mall during a scheduled performance in 2009.