The spread of fake news stories is one of the greatest controversies Facebook has faced in recent years, with some vocal critics even claiming the social media giant helped swing the presidential election by allowing this phony content to proliferate. One third-party plugin tried to help solve the problem by creating pop-up warning flags for fake news — but then Facebook blocked it. The site soon unblocked the tool, but the initial censorship raises an important question: what did Facebook find so offensive about this helpful feature?

TechCrunch incorrectly reported last week that the plugin, called B.S. Detector, might be a tool produced by Facebook itself. According to the plugin’s creator, that might be why links to the feature were banned.

“I believe they are doing this because of TechCrunch article that came out yesterday, falsely identifying a screenshot of my plugin as a Facebook feature under development,” Daniel Sieradski, the creator of the plugin, told TechCrunch. “It would seem I’ve caused them some embarrassment by showing them to be full of bull when it comes to their supposed inability to address fake news and they are punishing me for it.”

During the brief period that the tool was banned, a warning popped up to users who clicked on its link that the feature might be “unsafe.” Facebook soon corrected its mistake and restored B.S. Detector, but why was it taken down in the first place? The site hasn’t given an exact answer, but it’s troubling that it removed a tool dedicated to helping users like this.