In 1986, Cliff Stoll’s boss at Lawrence Berkeley National Labs tasked him with getting to the bottom of a 75-cent accounting discrepancy in the lab’s computer network, which was rented out to remote users by the minute. Stoll, 36, investigated the source of that minuscule anomaly, pulling on it like a loose thread until it led to a shocking culprit: a hacker in the system.Stoll then spent the next year of his life following that hacker’s footprints across the lab’s network and the nascent intern...