https://www.cnet.com/news/facebook-sued-by-russian-firm-linked-to-election-meddling/

In April, Facebook said it had taken down more than 270 pages and accounts operated by the IRA, a group Facebook CEO Mark Zuckerberg said "repeatedly acted deceptively and tried to manipulate people in the US, Europe, and Russia." In the past few years, governments, propagandists and internet trolls have used Facebook to spread false stories and influence elections. 

The IRA is affiliated with the Russian government and is known for creating fake online identities and entering into both sides of divisive political debates, according to allegations from FBI Special Prosecutor Robert Mueller. In February, Mueller charged the agency with conspiracy to defraud the US and "aggravated identity theft" for its activities around the 2016 election. In November 2017, Facebook said it would tell users which IRA-originated content they had interacted with.