The Free Speech Discussion Forum is an annual event that is designed to bring together prominent scholars from all over the world to discuss cutting-edge free speech issues. The 2021 meeting was hosted by the Johannes Gutenberg University of Mainz. Two major topics were discussed at the 2021 forum: "Robotic Speech" and "Contemporary Threats to Speech." The "Robotic Speech" topic included examination of such things as "chatbots," data-driven speech, "deep fakes," and the potential for internet speech to interfere with democratic elections. The "Contemporary Threats to Speech" focused on a variety of topics, including the growth and power of social media platforms. This compendium includes selected articles that were discussed at the Forum. It also honors the long-standing faculty exchange of the University of Mainz's School of Law and die Louis D. Brandeis School of Law at the University of Louisville, Kentucky.