Facebook Inc on Wednesday took down a network of pages and accounts used by a right-wing Brazilian activist group, cracking down on what it called a misinformation network ahead of elections in October.
Facebook said in a statement that it deactivated 196 pages and 87 accounts in Brazil for their part in "a coordinated network that hid behind fake Facebook accounts and misled people about the nature and origin of its content, all for the purpose of sowing division and spreading misinformation."
The statement did not identify the pages or users involved, and a Facebook representative declined to identify them.
However, sources told Reuters that the network was run by senior organizers from the Movimento Brazil Livre (MBL) or "Free Brazil Movement."
The MBL later said in a statement on Twitter that several of its organizers had been affected, confirming the Reuters report.
The group rose to prominence in 2016 leading protests demanding the impeachment of leftist former President Dilma Rousseff with an aggressive style of online politics that has helped to polarize debate in Brazil.
MBL representatives did not respond to multiple requests for comment. Their statement criticized Facebook for blocking several organizers without giving a full explanation, complaining that some of the banned accounts were using members' real names and personal information.
"Freedom of expression and democracy are pillars of the MBL. We will use all of the legal, political and media resources offered by democracy to recover the blocked pages and undo this persecution," the group said.
Facebook declined to comment on the criticism.
The deactivated pages, which together had more than half a million followers, ranged from sensationalist general news feeds to political fare with an openly conservative slant, carrying names such as Jornalivre and O Diario Nacional.
By misrepresenting the shared control of the pages, the MBL organizers were able to spread their coordinated messaging as if it were coming from various independent news outlets, according to sources who spoke on condition of anonymity.
Facebook said it took down the network in Brazil after a "rigorous investigation" because the profiles involved were false or misleading, violating its authenticity policies. The social network has a separate set of tools to discourage the distribution of fake news with help from outside fact checkers.
Facebook has been under heavy pressure to stop the use of fake accounts and other types of deception on its network.
The company last year acknowledged that the platform had been used for what it called "information operations" employing fake accounts and other methods to influence public opinion during the U.S. election in 2016, and pledged to crack down.
U.S. intelligence agencies say the Russian government engaged in a campaign to influence the U.S. presidential election, and cases of political groups using social media in deceptive ways have since emerged around the world.
There was no indication of foreign involvement in the MBL network taken down on Wednesday, the sources said.