Facebook is changing its rules on private groups amid growing criticism that some closed communities on the platform are uniting extremists and spreading fake news.

The company announced in a blogpost on Wednesday that it would take a more “proactive” approach in detecting problematic content in groups and will work to enhance transparency surrounding them.

“Being in a private group doesn’t mean that your actions should go unchecked,” Tom Alison, Facebook’s vice president of engineering said in a statement.

Facebook said it has built a new tool called Group Quality that will use artificial intelligence to scan groups for content that violates community standards. It will also give administrators more power over what goes into the groups and insight into why posts are removed through its new Group Quality tool.

Facebook will is also changing privacy settings to allow administrators to make groups either “public” or “private”, a move that would remove certain groups from search results, it said in a separate announcement.

Rather than helping to curb the rise of hate speech and misinformation, some critics worry, the changes may help push questionable content further underground. Facebook should give independent researchers access to similar tools so they can gain insight into what is happening in private groups, said Benjamin Decker, CEO of the digital investigations consultancy Memetica.

“Many of the groups I study are now changing their privacy status to be closed and not visible, making it more difficult for content violations to be identified by outsiders,” he said. “I am very concerned this will further allow conspiracy communities and violent extremists to further obfuscate their activity.”

Facebook said the new feature will find objectionable content even if administrators fail to flag it. Through the Group Quality tool, it will alert administrators to potentially violating posts and give more context into why it is being removed.

“There’s a misperception that private groups go unchecked just because they aren’t visible to the public,” Nir Matalon, a product manager on Facebook Groups said. “In reality, our proactive detection technology can find violations even if no one in the group reports it. We also have barriers in place to catch bad posts from people who have broken our rules before and are holding admins more accountable for what their members share.”

The new rules also rely on administrators of groups, who police content in these micro-communities, to help flag questionable content.

Facebook pushed its group and “community” features in a series of advertising campaigns in early 2019. But the rise of groups also allowed insulated communities to spread fake news and hate speech to millions of users. The company has faced repeated calls to curb the rise of anti-vaccination groups, where users can easily post misinformation about public health without repercussions.

Facebook has changed rules around groups several times in recent years, and new policies may represent a step in the right direction, said Sharon Kann, head of the Abortion Rights and Reproductive Health research team at Media Matters, but it remains to be seen if they will make a difference.

“We’re hopeful that this change means Facebook is taking seriously the spread of misinformation and harassment on the platform – something we know has continued in spite of other policy changes,” she said. “Once again, the question remains whether Facebook is committed to actively enforcing these policies when content or activity is in clear violation.”