The FBI has said the authorities in Sweden have been questioning the teen about attacks on Uppsala University computers. It is still unclear whether the 16-year-old boy had been working alone or as part of a team.
Last year, portions of the source code of Cisco's Internetwork Operating System (IOS) were discovered on an Internet Relay Chat (IRC) channel. The code portions were from versions 12.3 and 12.3t of the operating system.
The code forms the basis of networking hardware that controls most of the internet. A breach in the code could have massive implications for the security of the internet. It is reported in the New York Times that knowledge of the code had been used to mount attacks on a number of high-security government networks, including NASA and the US Army.
According to the FBI, since the police caught up with the alleged hackers, "criminal activity has stopped".
Earlier this week, Iowa State University unveiled a new research lab designed to realistically simulate internet attacks in order to better study their effects and lead to improved defenses.