Facebook CEO Mark Zuckerberg announced the platform took down 270 accounts and pages that originated from the Internet Research Agency, the Russian “troll factory” that is said to be responsible for interfering in foreign elections, including the 2016 presidential vote in the United States. This time, their meddling was directed at Russian citizens.

“We’ve found the IRA has been using complex networks of fake accounts to deceive people. While we respect people and governments sharing political views on Facebook, we do not allow them to set up fake accounts to do this,” Zuckerberg said. The pages and accounts the company removed, he said, were taken down not because of the content they shared, but because of who runs them. “We don’t want them on Facebook anywhere in the world,” Zuckerberg wrote.

The IRA accounts were targeting people in Russia and Russian-speaking countries such as Azerbaijan, Uzbekistan and Ukraine. Some pages, Zuckerberg said, were run by Russian news outlets that were controlled by the IRA, and had as many as 1 million followers. Facebook will release a tool that will let you check if you interacted with an account controlled by the troll factory.

After it was determined the IRA had targeted more than 100 million Americans between 2015 and 2017 on Facebook, the company took down the accounts of the perpetrators, and has been working with other governments to prevent similar meddling. “Security isn’t a problem you ever fully solve,” Zuckerberg wrote in his post. The next big challenges for the platform are the 2018 midterm elections in the US, as well as elections in Mexico and Brazil.