The social media giant announced in a blog post on Wednesday that it had banned the accounts, apps, and pages related to the NYU Ad Observatory, a project by Cybersecurity of Democracy.

Over the last several years, we’ve used this access to uncover systemic flaws in the Facebook Ad Library, identify misinformation in political ads including many sowing distrust in our election system, and to study Facebook’s apparent amplification of partisan misinformation.”

Facebook has also effectively cut off access to more than two dozen other researchers and journalists who get access to Facebook data through our project, including our work measuring vaccine misinformation with the Virality Project and many other partners who rely on our data.