Our reliance on GPS makes us vulnerable

We all carry GPS technology around in our pockets. But there’s a lot more to the 'Global Positioning System' than meets the eye. GPS was originally conceived as a military product, one designed to drop enormously powerful bombs with staggering precision. It now underwrites everything from rideshares to traffic light systems, international banking and supply chains. Our over-reliance on it makes us incredibly vulnerable. Guest: Katherine Dunn, journalist and author. Her new book is Little Blue Dot: How the Global Positioning System Shaped the Modern World Producer: Julie Street