Even without her massive record sales and recent Grammy nominations, Lady Gaga was a force this year. She constantly made headlines with her too-wild-to-imagine antics (flipping off photographers at a New York Mets baseball game in June; wearing a dress made out of meat to the MTV Video Music Awards in September). But what makes Gaga the year's Most Provocative Celebrity is the sheer impact of her antics. In 2010 she dominated cyberspace, becoming the most followed person on Twitter and the first artist to reach a billion video views on YouTube. And Lady Gaga wasn't afraid to use her massive platform to effect social change. She led campaigns to stop bullying and to end the military's "Don't Ask, Don't Tell" policy. For making headlines, provoking strong love-her-or-hate-her reactions, and, in effect, taking over the world this year, Lady Gaga is "Showbiz Tonight's" Most Provocative Celebrity of 2010.