A Russian-funded campaign of misinformation on Facebook sought to promote division in the United States during this year’s Presidential election.
The social network announced in a blog post that $100,000 (£77,000) was spent on around 3,000 ads over a two-year period up to May 2017 to promote divisive messages on subjects such as LGBT, race, immigration and gun rights.
Chief security officer Alex Stamos wrote that the ads did not specifically reference the election, voting or a particular candidate.
Facebook said it was co-operating with a US investigation into the matter, handing over its evidence to special prosecutor Robert Mueller.
“There have been a lot of questions since the 2016 US election about Russian interference in the electoral process,” wrote Stamos.
“In April we published a white paper that outlined our understanding of organized attempts to misuse our platform. One question that has emerged is whether there’s a connection between the Russian efforts and ads purchased on Facebook.
“These are serious claims and we’ve been reviewing a range of activity on our platform to help understand what happened.
“In reviewing the ads buys, we have found approximately $100,000 in ad spending from June of 2015 to May of 2017 — associated with roughly 3,000 ads — that was connected to about 470 inauthentic accounts and pages in violation of our policies.
“Our analysis suggests these accounts and pages were affiliated with one another and likely operated out of Russia.
“We don’t allow inauthentic accounts on Facebook, and as a result, we have since shut down the accounts and pages we identified that were still active.
“About one-quarter of these ads were geographically targeted, and of those, more ran in 2015 than 2016.
“The behavior displayed by these accounts to amplify divisive messages was consistent with the techniques mentioned in the white paper we released in April about information operations.”