A disinformation network with ties to China used hundreds of fake social media accounts – including one belonging to a fictitious Swiss biologist – to spread an unfounded claim that the U.S. pressured scientists to blame China for the coronavirus, Facebook said Wednesday. The company based in Menlo Park, California, did not directly attribute the network to the Chinese government. But it noted employees of Chinese state-run companies, and the country’s state-run media, worked to amplify the misleading claims, which were soon the subject of news headlines in China. “In effect it worked like an online hall of mirrors, endlessly...