In 2010 U.S. Customs and Border Protection agents at the Canadian border stopped an American student on his way home to Brooklyn. Pascal Abidor was returning from McGill University in Montreal, where he was working on his Ph.D. Unfortunately for him, his doctorate is in Islamic Studies, and when the officers asked him to open his laptop and type in his password, they found images of Hamas and Hezbollah rallies, collected as part of his research into modern Lebanese Shiism. He was detained for several hours, and his laptop was impounded. When he finally got it back—following intervention from the American Civil Liberties Union—it had been forced open, and the contents, which included personal information as well as academic material, had been copied wholesale. The subsequent court battle, which the ACLU lost, resulted in a ruling with consequences that were literally far-reaching. A judge affirmed not only that Border Patrol agents had the right to search travelers’ physical and electronic belongings without reasonable suspicion of wrongdoing but also that they could do so far beyond …