By the early 80s, kids were already trawling the message boards of the Internet for perverse kicks. Well before Star Ways Kid or "flash mobs," one of the first online fads was the "Purity Test," a series of questions to rate your moral purity, from the raunchy ("Ever had sex in your parents' bedroom?") to the absurd ("Ever snorted cocaine off the dashboard of a car doing 80 mph?"). The tests would be printed out, brought to school, and pored over...