Simon Van Zuylen-Wood

When it comes to figuring out how Facebook actually works—how it decides what content is allowed, and what isn’t—the most important person in the company isn’t Mark Zuckerberg. It’s Monika Bickert, a former federal prosecutor and Harvard Law School graduate. At 42, Bickert is currently one of only a handful of people, along with her counterparts at Google, with real power to dictate free-speech norms for the entire world. In a meeting room called "Oh, Semantics", she sits at the head of a long table, joined by several dozen deputies in their 30s and 40s.