China’s leader, Xi Jinping, may have visions of serving as president for life, but first he must get rid of thousands of dissidents eager to overthrow him after lockdowns mandated by his “zero-COVID” policy. Xi is deploying every instrument he has to repress an uprising in danger of spreading before he gets it totally under control. While the police pounce on protesters, Xi’s technical wizards do their best to shut down every conceivable opening on the internet. Try to find what’s happening in major cities via Twitter by punching in the Chinese characters for the capital, Beijing, and the business...