Facebook touts itself as a platform built for the open sharing of thoughts and opinions. However, it often finds itself in trouble for the content it allows on its pages — and the posts it takes down. That’s what happened this week when the site censored a post from a black woman detailing a racist incident she and her children suffered

The woman, Francie Latour, was in a grocery store when a white man uttered a racial epithet at her two young sons. Understandably upset, she posted about the incident on Facebook. However, the site removed her post within 20 minutes, telling her that it violated Community Standards.

And Latour isn’t alone. Activists say that because Facebook’s rules for regulating speech are so unclear, minorities often end up the target of hate speech removal.

“In the era of mass incarceration, you come into this digital space — this one space that seems safe — and then you get attacked by the trolls and put in Facebook jail,” Stacey Patton, a journalism professor at Morgan State University, told The Washington Post. “It totally contradicts Mr. Zuckerberg’s mission to create a public square.”

Thankfully, Latour’s post was restored to Facebook within 24 hours. But why was she shut down in the first place? With the company’s lack of transparency, the answer isn’t clear.