“Twitter must serve as a public town square”, Elon Musk said when he tried to buy the platform. But what would this Twitter-as-town-square look like? What are the boundaries of online freedom of expression? And who determines what can be said there? Together with journalist Ernst-Jan Pfauth, writer and activist Jillian C. York goes in search of the value system behind such digital platforms. How does content moderation relate to freedom of expression?