A local market watchdog summoned 16 e-commerce platform operators – including a branch under Alibaba Group Holding, Meituan’s group-buying business, and Vipshop – to warn them against “unfair competition” activities and other business malpractice, as Beijing’s ongoing antitrust crackdown weighs on Big Tech companies during this year’s Singles’ Day festival. In a meeting last Friday, the Guangdong Administration for Market Regulation accused the companies of various irregularities including selling fake products, false advertising and poor after-sales services, according to a report published on Tuesday by the state-run China Central Television (CCTV). Alibaba’s Singles’ Day is not the draw for online…