https://www.cnet.com/news/facebook-steps-up-fight-against-fake-news-in-groups-and-messaging/

The company said that in the coming weeks it'll start looking at how administrators and moderators of Facebook groups decide what content to keep up. That'll help Facebook determine whether a group is violating the social network's rules. It's also releasing a Group Quality feature so users can see what content was removed and flagged, including fake news. Facebook groups that repeatedly share misinformation will show up lower on the social network's News Feed.

Facebook said it's been using technology, human reviewers and user reports to flag and remove content in groups that violates its rules, even if the groups aren't public.