S arah Wynn-Williams’s memoir documenting her seven years working at Facebook opens, unexpectedly, with a shark attack. The New Zealander was 13 years old and swimming in the sea when the shark bit her torso and shook her from side to side. She lived to tell the tale, but her near-death experience awakened in her a desire to leave the world better than she found it. Wynn-Williams went on to take a job at Facebook’s public policy department in 2011, having seen the potential of the platform as a global meeting place. But what she found was a senior staff high on power and untroubled by ethical concerns such as privacy or the dissemination of hate speech and misinformation. All were resistant to political interference and dedicated to rapid expansion, no matter the consequences, claims that Meta has called out of date and false.…