The FBI is questioning a teenager in Sweden in connection with a hacking attack on a number of high security computer systems that include the US military and NASA.
Police have traced the attacks to a university which the 16-year-old was charged with hacking into in March this year.
It is still unknown whether the teenager worked alone or with others. The FBI has said that the hacks could be connected to the robbery of Cisco's Internetwork Operating System source code, which was stolen and published on a Russian Web site last year.
According to a report in The New York Times, it is still unclear how much information, if any, was stolen via the hacks. The attacks were first seen in April 2004 when several US supercomputers connected to the high-speed TeraGrid were penetrated.