The French arrest and detention of Telegram co-founder Pavel Durov on poorly specified charges related to failures of content moderation and compliance with law enforcement is an outrage—and a reminder that, at least on the surface, Europe and the United States have fundamentally different approaches to unregulated speech that go back centuries. Recall that John Milton’s world-changing defense of an unlicensed press, Areopagitica, pointedly excluded Catholics while his former Cambridge classmate Roger Williams was living in what would become Rhode Island and defending “soul liberty” for all pe…