Like other kids in the Bedford-Stuyvesant neighborhood of Brooklyn, Ejovi Nuwere grew up among thugs and drug dealers. When he was eleven, he helped form a gang; at twelve, he attempted suicide. In his large, extended family, one uncle was a career criminal, one a graduate student with his own computer. By the time Ejovi was fourteen, he was spending as much time on the computer as his uncle was. Within a year he was well on his way to a hacking career that would lead him to one of the most audacious and potentially dangerous computer break-ins of all time, secret until now.

Before...