See http://www.cidrap.umn.edu/news-perspective/2020/04/commentary-masks-all-covid-19-not-based-sound-data http://www.cidrap.umn.edu/news-perspective/2020/04/com

See http://www.cidrap.umn.edu/news-perspective/2020/04/commentary-masks-all-covid-19-not-based-sound-data http://www.cidrap.umn.edu/news-perspective/2020/04/commentar... for a reliable "con" side of the debate. Note in particular that cloth masks were tried and failed during the Spanish flu epidemic.