Rooney Mara dedicated her entire being to the part of Lisbeth Salander for the filming of "The Girl With The Dragon Tattoo." She even went so far as to really get her nipple pierced for real. "I’m naked quite a lot in the movie, and I thought, she has [a nipple piercing] in the book, and she should have it [in the movie] ... Because of all the tattoos and the makeup and the piercings, and the physical transformations my body has to go through, it would always feel sort of like I was in costume, even if I was naked ... It just felt like a good one to get - a necessary one to get," she told Allure of her decision to go through with the piercing. I wonder if she's planning to keep it? Click through to see more celebs with naughty piercings.