Facebook has removed more than 500 Russian-linked pages, groups and accounts which it said were “engaged in coordinated inauthentic behavior,” according to a statement on the company’s blog. The social media giant said it had identified two networks behind the fake accounts, one of them apparently linked to the Kremlin-funded Sputnik news agency, which was targeted multiple European and Asian countries. Another network was targeting Ukraine. “The Page administrators and account owners primarily represented themselves as independent news Pages or general interest Pages,” wrote Nathaniel Gleicher, Facebook’s Head of Cybersecurity. Their goal was to “mislead others about who they were and what they were doing.” The decision to remove the accounts was based on their manipulative behavior, he said, not their actual content. It’s the latest in a series of measures it has taken against fake accounts, following revelations of how Facebook and other platforms were exploited by Russia to influence the 2016 US election. But despite hiring large numbers of people to detect and take down fakes, Gleicher admitted that the company is still playing catch-up with disinformation: “[A]s we’ve said before, it’s an ongoing challenge because the people responsible are determined and well funded. We constantly have to improve to stay ahead. That means building better technology, hiring more people and working more closely with law enforcement, security experts and other companies.”