It's just past midnight and a Vienna rave is at full-throttle, packed with sweaty dancers pulsing to an electronic beat. Off to the side, visible through the flickering lights, a long queue snakes out from a covered booth. The ravers in line are all carrying illegal drugs. One by one, they enter the booth, take out one of their pills, and scratch it on a tiny piece of sandpaper. A scientist behind the counter pops the sandpaper back into a glass vial, whispers a number in the person's ear, and disappears. About twenty minutes later, the scientist posts a card on a board with the number and the pill's full chemical contents.