For decades, in the summertime, America has confined certain of its youth in what are essentially open-air heat camps. In city after city, camp-form is established through the enactment of warm-weather juvenile curfews which keep the youth at home or in state-sponsored centers during summer nights and, increasingly, during days as well. Local governments justify these curfews with general notions of “public safety,” including to protect the youth they confine. But the laws are not benevol...