There’s a lot of fake content and spam on Facebook, and as the Russian propaganda scandal proved during the 2016 election, some of it is created by hostile foreign powers to influence us. Facebook revealed the existence of another such campaign this week when it announced it has taken down 82 pages and accounts with ties to Iran responsible for posting inflammatory political content.

Thankfully, Facebook acted quickly to remove these pages, shutting them down about a week after they were detected. The company was able to identify the content because of similarities it shared with previous Iranian attacks. Facebook also shared its findings with U.S. law enforcement officials and Congress.

According to Facebook, the misinformation campaign relied upon cybercriminals impersonating regular users.

“The Page administrators and account owners typically represented themselves as US citizens, or in a few cases UK citizens — and they posted about politically charged topics such as race relations, opposition to the President, and immigration,” Facebook Head of Cybersecurity Policy Nathaniel Gleicher wrote in a blog post.

However, even though the propaganda was swiftly detected, it still reached over 1 million users—an alarming amount of people for such a short amount of time. While Facebook is getting faster and removing harmful content, it’s still far too easy for the platform to be exploited in the first place.