WASHINGTON • Facebook is not taking photos and videos at face value. It is expanding efforts to scan them for evidence that they have been manipulated.
In 17 countries, including the United States, Facebook said it had deployed its powerful algorithms to "identify potentially false" images and videos, then send those flagged posts to external fact-checkers for further review.
The company is trying to stamp out content that has been doctored, taken out of context or paired with misleading text.
In one of the examples Facebook shared, fact-checkers in Mexico previously identified a "false photo" of a local politician whose face had been Photoshopped onto an American green card, wrongly suggesting he is a United States citizen.
In another, a news outlet in India debunked a photo that included a caption calling the country's prime minister the "seventh most corrupted" in the world - a fact attributed to "BBC News Hub", which is not part of the BBC.
Facebook's announcement is part of a series of changes designed to stop the spread of misinformation on its site two years after the 2016 American presidential election, when Russian agents created and shared divisive political messages - including photos - that reached more than 100 million US users.
But photos and videos represent one of the toughest challenges facing Facebook and its tech peers, given that visual content leaves such lasting impressions on users.
The site's two billion active monthly users upload 350 million images every day, Facebook said, and finding and combating manipulated images and videos is tougher than it is with plain text.
Social media sites must also grapple with the rise of new disinformation techniques, such as "deepfakes" - videos that harness the power of machine learning and artificial intelligence to make a person appear to say or do something that never took place.
The automated detection of deepfakes and similar computer-created forgeries have become something of a holy grail for many in Silicon Valley and beyond.
The Defence Advanced Research Projects Agency, the military's high-tech research arm, is leading initiatives designed to build forensic tools that can automatically spot clues among faked videos, including by assessing lighting, image artefacts or other inconsistencies.