China has launched a multipronged attack on its tech companies, threatening to curb their ability to list in the United States, seeking to tighten up regulation of their use of algorithms and sidelining their cloud computing businesses in a major city. In another move amid a wave of regulations on the tech sector announced in recent months, Beijing has also cracked down on what it described as a “chaotic” celebrity fan culture, imposing new restrictions on already tightly controlled content in China. The moves further clip the wings of Chinese tech behemoths such as Alibaba Group Holding Ltd. and Tencent…