To profile or not to profile? Some recent suspicious incidents involving mass purchase of cell phones by Middle Eastern men have given this debate a new urgency. On Tuesday, terrorism charges were dropped against two Muslims from Dearborn, Michigan, who had been arrested in Ohio. Ali Houssaiky and Osama Sabhi Abulhassan had been stopped for a traffic violation a week before; in their car, sheriff’s deputies found $11,000 in cash, airline passenger lists, material about airport security procedures, and twelve cell phones. It turned out that they had bought 600 cell phones recently. Cell phones can be used as detonators....