The former employees from several African countries allege poor working conditions including low pay and insufficient mental health support.

On the verge of tears, Nathan Nkunzimana recalled watching a video of a child being molested and another of a woman being killed.

Eight hours a day, his job as a content moderator for a Facebook contractor required him to look at horrors so the world wouldn’t have to. Some overwhelmed colleagues would scream or cry, he said.