How far will China go in monitoring and controlling its tech giants? Investors fear regulatory tightening following several initiatives announced against them in recent weeks. As late as Tuesday, the share price of Tencent, an internet heavyweight and active in various fields, fell more than 10% on the Hong Kong stock exchange. In the morning, a state newspaper, Economic Information Daily, had treated online games, a specialty of the multinational, “mental opium” and “electronic drug”. Its competitor NetEase also fell by almost 8%. The Bilibili site, popular with fans of cartoons, manga and video games, lost more than 3%. The...