Facebook’s semi-independent Oversight Board is scrutinizing the company’s XCheck (or cross-check) system, which permits famous or powerful users to be held to more lenient behavior rules than other users. The inquiry, which calls out “apparent inconsistencies” in the social media firm’s decision-making, follows an investigative report by The Wall Street Journal. XCheck was initially designed as a quality control system for sanctions against high-profile users, including celebrities, politicians and journalists. It eventually grew to encompass millions of accounts, some of whom were “whitelisted,” which rendered them immune from disciplinary actions.

A 2019 internal Facebook review characterized the whitelisted status as “not publicly defensible.” Facebook at one point wrote to the Oversight Board that the whitelisting system affected “a small number of decisions.” In a blog post, the Oversight Board said it was exploring whether Facebook has “been fully forthcoming in its responses in relation to cross-check, including the practice of whitelisting.”

“This information came to light due to the reporting of The Wall Street Journal, and we are grateful to the efforts of journalists who have shed greater light on issues that are relevant to the Board’s mission,” the post continued. “These disclosures have drawn renewed attention to the seemingly inconsistent way that the company makes decisions, and why greater transparency and independent oversight of Facebook matter so much for users.”

The Oversight Board is an outside body created by Facebook to police accountability of the social media giant’s enforcement systems. The Board said having sought a reaction from Facebook’s leadership it “expects a briefing in coming days,” The Wall Street Journal reports.

A Facebook spokesman has previously told WSJ that criticism of how it executed the the whitelisting system “was fair, but added that it was designed ‘for an important reason: to create an additional step so we can accurately enforce policies on content that could require more understanding.’” Facebook is phasing out the practice of whitelisting, he continued.

Separately, Senator Richard Blumenthal (D-Connecticut) says lawmakers are seeking a C-suite Facebook representative to testify at a September 30 hearing, to respond to WSJ’s expose of  internal Facebook research on the largely negative effects of Instagram on teen girls.

“The simple fact of the matter is that Facebook has known for years that Instagram is directly involved in an increase in eating disorders, mental health issues, and suicidal thoughts, especially for teenage girls,” Blumenthal said at a Senate Judiciary Committee hearing. Facebook, he added, had previously misled Congress in about its findings as to the impact of its platforms on mental health.

Facebook privacy and public-policy vice president Steve Satterfield disagreed with Blumenthal’s assessment, adding, “The safety and well-being of teens on our platform is a top priority for the company.”

Senator Mike Lee (R-Utah) said he felt WSJ’s reporting underscored that Facebook lacks competition: “This too looks like the behavior of a monopolist, a monopolist that is so sure that its customers have nowhere else to go that it expresses a reckless disregard for quality assurance, for its own brand image, and even just being honest with its users about the obvious safety risks.”