Alias: Kuji (Bevan) and Datastream Cowboy (Pryce)
Age: 41 (Bevan) and 35 (Pryce)
This British hacking duo took the U.S. government for a ride when they attacked the Pentagon's network for several weeks in 1994. They copied battlefield simulations from Griffiss Air Force Base in New York, intercepted messages from U.S. agents in North Korea, and got access into a Korean nuclear facility. Pryce was a 16-year-old then, and Bevan was 21 (he's thought to have been tutoring Pryce).
The hacking attacks were especially troublesome for the U.S. government because they couldn't tell if the duo was using their system to hack into a South or North Korea—if it were North Korea, the attacks could've been seen as an act of war. Luckily, South Korea was the hackers' target, and after an international investigation, they were arrested in the following year.