"Informationsvielfalt und Algorithmenmacht: zur Relevanz von Intermediären für die Meinungsbildung [Diversity of Information and the Power of Algorithms: On the Relevance of Intermediaries on Opinion Formation] ", lecture by J.-H. Schmidt at the conference "Ganz meine Meinung? Politische Meinungsbildung in sozialen Netzwerken [Exactly My Point of View? Political Opinion Formation in Social Networks]", organised by the media authorities and the Media Authority of North Rhine-Westphalia (LfM) on 8 March 2017 in Berlin.