"Since September, a public-school district in Florida has been taking fingerprint scans at the entrance to schools as a way to monitor attendance. The scans are compared against a database of students to detect truants. As in most highly intrusive school policies, parents are thrown a bone of control by allowing them to request an “opt out” for their children. An opted-out student needs to pursue a teacher and go through a special sign-in every day. In terms of time, convenience, and avoidance of stigma, students have a strong incentive to comply quietly."