Thirty WeChat groups have been banned for spreading rumors about the COVID-19 pandemic in Shanghai, according to the city's cyberspace watchdog.Twenty-three WeChat users, who were identified as sources of some of the rumors, have also been punished since April 8, the office of cyberspace affairs in Shanghai said on Thursday.Several people have so far been given administrative penalties by city police for making and spreading rumors since the pandemic resurgence in March.