The debate between Twitter and Facebook on whether they should police the content of posts is need to be understood in the context of the mechanisms social network companies use to rank contributions and disseminate information the specificity of US regulation of publishers and media content providers I wrote one contribution on ESSEC Knowledge in July 2020 and three articles (in French) in Libération and La Libre Belgique in 2016-19 that help to shed some light. ESSEC Knowle