In its near 400-page S-1 filing for an initial public offering, Facebook had to reveal not only details about its revenue figures but also the now well-known names that helped build the social network from a dorm room side project into a global company. Not all of them are flattering. We knew that Sean Parker likes to party and Mark Zuckerberg has a dog. But did you know that Facebook can't live without Sheryl Sandberg?