President Obama speaking at a rally for Hillary Clinton at the University of Michigan on November 7. Associated Press

Even President Obama has had enough of fake news on Facebook.

Obama criticized how "crazy conspiracy theorizing" is spread on social networks like Facebook while speaking at a rally for Hillary Clinton at the University of Michigan on Monday.

"And people, if they just repeat attacks enough, and outright lies over and over again, as long as it's on Facebook and people can see it, as long as its on social media, people start believing it," he said. "And it creates this dust cloud of nonsense."

A recent BuzzFeed investigation found that 38% of posts shared from three large right-wing politics pages on Facebook included "false or misleading information," and that three large left-wing pages did the same nearly 20% of the time. A follow-up investigation by BuzzFeed revealed how teenagers in Macedonia create fake, pro-Trump news stories that go viral on Facebook.

Reports of fake news stories surfacing on Facebook spiked after the social network fired the human editors who ran its Trending news section. Facebook has said it's working to better filter out false and misleading stories from the News Feed but has yet to introduce any major changes.