The complaint on Thursday by the board, a group of outsiders that oversees Facebook’s content moderation processes, follows a Wall Street Journal article in September that revealed Facebook didn’t as readily sanction celebrities, politicians, and other prominent figures for violating its rules as with regular users. Instead, VIPs were policed under an entirely separate system known as “cross-check,” or “XCheck.”

While Facebook previously told the board that cross-check applied only to a “small number of decisions,” it actually included at least 5.8 million users in 2020. The board also said it was “not acceptable” that Facebook failed to mention XCheck when it banned former President Donald Trump from its service earlier this year, and provided details about it only when asked. 

The cross-check system protected public figures whose posts included harassment, explicit content, or misinformation. In one case, moderators were kept from removing so-called revenge porn posted by Brazilian soccer star Neymar for over a day. The photos were viewed by 56 million users and reposted over 6,000 times before eventually being taken down; Neymar’s accounts were left active. Additionally, posts by well-known individuals had claimed that vaccines were deadly and that Hillary Clinton had covered up “pedophile rings.”

The board also expressed concerns about Facebook’s ambiguous content moderation policies and removal of posts by its general users, citing cases in which users were left guessing about why exactly their content was removed. 

“Right now, it’s clear that by not being transparent with users, Facebook is not treating them fairly,” the board said in its report. “The board is deeply concerned with the impact on users and the implications for freedom of expression around the world.”

In response to the report, a Facebook spokesperson told Fortune: “We thank the board for their ongoing work and for issuing their transparency report. We believe the board’s work has been impactful, which is why we asked the board for input into our cross-check system, and we will strive to be clearer in our explanations to them going forward.”

The report comes at a time when Facebook has already come under fire for ignoring Instagram’s harmful effects on young girls and providing a weak response to drug cartel and human trafficking activity on its service. 

The oversight board plans on calling for public comments in the coming days to “engage with civil society globally.” Facebook has also agreed to share documents and information regarding cross-check, which the board will eventually use to issue recommendations for changes it believes the company should undertake. 

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