The world is a dangerous place, but intelligence community leaks and vague scares have no place in a serious debate about protecting flights from terrorists. Policymakers should explain clearly why each regulation is adopted: What the danger is and why other obvious measures — such as turning on laptops rather than putting them in checked luggage — cannot be used. Neither the U.S. nor the U.K. has provided a satisfactory explanation for their initial laptop bans. "We have highly classified intelligence and it's none of your business what it is" isn't good enough.