Facebook Blocks Iran-Linked Bid to Sway U.S., British Politics

Facebook said Friday it had blocked an Iran-linked effort to influence U.S. and British politics with posts about charged topics such as immigration and race relations.

Facebook head of cybersecurity policy Nathaniel Gleicher said the platform had identified 82 pages, groups and accounts that originated in Iran and violated policy on coordinated inauthentic behavior.

Gleicher said there was "overlap" with accounts taken down earlier this year and linked to Iran state media, but the identity of the culprits had yet to be determined.

"It's often hard to know who is behind this type of activity," Gleicher said in a telephone briefing.

Account owners tried to hide their identities by passing themselves off mostly as U.S. citizens, and in a few cases as British citizens, according to Gleicher.

Posts on the accounts or pages, which included some hosted by Facebook-owned Instagram, focused on "sowing discord" via strongly divisive issues rather than on particular candidates or campaigns.

The purge involved 30 pages, 33 accounts and three groups at Facebook, as well as 16 accounts at Instagram.

Slightly more than a million accounts followed at least one of the pages, with the majority of the engagement taking place over the past year, according to Facebook.

Accounts involved in the influence campaign hosted seven real-world events, but Gleicher did not reveal details about whether they took place or how well they were attended.