Like whistleblower Frances Haugen, these Facebook employees warned about the company’s problems for years. No one listened.

In November 2020, another integrity researcher, Lindsay Blackwell, wrote a long resignation letter on the company’s chat system. Blackwell’s project, called WoW, or the Worst of the Worst, was an effort to refine the company’s hate speech detection algorithms after internal research found that users want Facebook to police some very harmful forms of hateful speech, such as attacks on Muslims or LGBTQ people, more rigorously than others, according to a person familiar with the project, who spoke on the condition of anonymity to describe sensitive matters. After the team spent more than a year engineering a solution to reorient the algorithms, managers and senior leaders dramatically redefined the project, arguing that prioritizing the safety of marginalized groups would be too political, the person said. Blackwell declined to comment.