Facebook continues to publicaly defend its practices when it comes to eliminating fake news and other kinds of spammy content, but according to a new report released this week, the company still has its work cut out for it in a big way.

Online tracking firm NewsWhip revealed that the fourth most-engaged-with story on Facebook during the first week of September was a fake. (The article claimed Michael Jordan had resigned from Nike’s board, and it came from a well-known source of online trolling.) Also, in the realm of food content, the second most-popular post from May to July this year was a hoax claiming Burger King uses horse meat in its products.

“We’ve seen some questionable, low-quality content going ultra-viral over the past few months,” NewsWhip’s Gabriele Boland wrote in the site’s August report.

While users can report fake content to Facebook for removal, and Facebook’s own algorithms handle a lot of the deletions automatically, it’s clear this is still a major problem for the company. Facebook has worked to limit spam ahead of the 2018 midterm elections, but if some of the most popular content shared on the entire platform is fake, it needs to do better.