Abstract: How should we think about the relationship between copyright and the First Amendment? Many answers have been proposed to that question, and this short essay does not attempt a comprehensive assessment of the debate. Rather, it examines the similarities and divergences between copyright and First Amendment principles using two points of comparison: the public forum and the public domain. A "public forum" in First Amendment law is a place held in trust by the government for use by the people, whether generally (a traditional public forum) or for specific topics (a limited public forum). By "public domain," I refer to various concepts of freedom to use expression, information and other intangible intellectual goods, rather than to real property. The public forum and the public domain are places that belong to everyone, because they belong to no one, from which people cannot be excluded on the grounds that a property owner wishes to exclude them. The history and complications of public forum doctrine offer some cautionary lessons for proponents of an expansive public domain in copyright.