Philip Gabriel Pettersson, 21, was indicted on one count of intrusion and two counts of misappropriation of trade secrets. He was also indicted on two counts of intrusion involving NASA. The U.S. Department of Justice's Criminal Division and Joseph Russoniello, attorney for the Northern District of California, announced the indictment after an investigation by the Federal Bureau of Investigation and other agencies.

IOS runs Cisco's routers, which handle most of the routing of packets on the Internet. Versions of the code are also at the heart of Cisco LAN switches and other products. In May 2004, parts of the IOS source code were briefly posted to a Russian Web site. Some observers said then that the theft might threaten the Internet by giving malicious hackers a glimpse into Cisco's proprietary software.

The Justice Department identified Pettersson as "Stakkato," the name used by a hacker linked to numerous attacks around the same time. It said Pettersson intentionally intruded into Cisco's network between May 12 and May 13, 2004, and misappropriated IOS code. Cisco has said it believes no customer information, partner information or financial systems were affected. Company officials were not immediately available for comment.

Pettersson is also accused of intrusions in 2004 at NASA facilities, including the Ames Research Center and the NASA Advanced Supercomputing Division, which are located in Silicon Valley. Those crimes allegedly took place on May 19, May 20 and Oct. 22 of that year.

Each count of intrusion and theft of trade secrets carries a maximum penalty of 10 years in prison, three years of supervised release and a US$250,000 fine.