> Just to be clear, unless a PreCheck passenger is randomly tagged for a more thorough check, he or she need only avoid setting off a metal detector to gain access to the secure areas of airports. In other words, these travelers could carry a pound of C-4 plastic explosive in their pockets and get onto any airplane in America.

Let him. We could hand out C-4 to everybody during boarding. Without a detonator, the terrorist would have to gag each passenger his pound of might-as-well-be Play-Doh.