A cellphone makes a convenient detonator for an improvised explosive device. But it’s also one of the most conveniently trackable devices under the eye of American law enforcement.
Less than 48 hours after a bomb exploded in a dumpster on a street corner in the Chelsea neighborhood of New York—and another device a few blocks away failed to explode—police have tracked the attack to New Jersey resident Ahmad Khan Rahami. At least one crucial link that investigators seem to have made came from the cellphone planted in one of the bombs. The incident is a reminder of just how difficult it is to anonymously use a cellphone in America—whether to sell drugs, make an untraceable call to a journalist, or explode a deadly weapon in downtown Manhattan.