For Itzel Schnaas, a 31-year-old professional ballet dancer in Mexico City, going public was her insurance policy. If the plan worked, she believed a world-famous public intellectual, with ties to Mexico’s government and major media conglomerates, would be exposed as a sex offender, and she could be protected from him and his powerful friends. They couldn’t go after her if the world was watching, especially if other women came forward too. On Feb. 15, she posted a nearly seven-minute YouTube video excoriating the man: “It turns out that I had barely been born when you started violating women and sowing fear to obtain their silence, you miserable a–hole,” she says in Spanish. “You ought to be scared of us. Because I am certain that many other women are going to add their accusations to this one.” [time-brightcove not-tgx=”true”] They did. Since then, 36 women have publicly accused Andrés Roemer, leveling charges of sexual harassment, abuse and rape on social media and in...