On her first day, when Losse entered the office, she saw a few men but only one other woman, an administrative assistant. She also spotted various pieces of graffiti featuring well-endowed women. "'We had to move the really graphic painting to the men's bathroom because someone complained,' an engineer told me as he gave me a tour of the tiny office," she wrote. "He said this with the slight mocking disapproval that was my new colleagues' default tone in response to anything that resisted their power.... I could see that it was, in a sense, a test: If you couldn't handle the graffiti, or the unrepentantly boyish company culture it represented, the job wasn't going to work out."

The price of Facebook shares is displayed as the company goes public.
Richard Drew/AP