Thanks to the Symposium organizers and attendees for their input. I am indebted to Vicki Been, Michael Cahill, Clay Gillette, David Golove, Lucy Gratwick, Rick Hills, Ted Janger, Gerald Korngold, Bill Nelson, and Nelson Tebbe for stimulating conversations about the topic. Thanks to Gideon Parchomovsky and to the junior faculty at Brooklyn Law School for feedback on an early draft.