Last month, Brian Kelly of Carlisle, Pa., was riding with a friend when the car he was in was pulled over by a local police officer. Kelly, an amateur videographer, had his video camera with him and decided to record the traffic stop. The officer who pulled over the vehicle saw the camera and demanded Kelly hand it over. Kelly obliged. Soon after, six more police officers pulled up. They arrested Kelly on charges of violating an outdated Pennsylvania wiretapping law that forbids audio recordings of any second party without their permission. In this case, that party was the police...