Years ago, a colleague of mine sold stereo equipment at a regional electronics store outside of Tacoma, Wash. One night, the staff was preparing to lock things up when a scruffy-looking young man entered. He was dressed much more casually than the typical customer: torn jeans, a soiled sweatshirt and a ratty ball cap. He sauntered through the stereo department with his hands deep in his pockets, glancing at products seemingly beyond his economic status...