A British man has been arrested in connection with the theft of source code from Cisco Systems.
Cisco hardware helps the net keep going
The 20-year-old was arrested on 3 September following police raids on homes in Manchester and Derbyshire.
The man has not been identified or charged and has been bailed pending an appearance in court in November.
The theft of the core software that controls much of the net's hardware came to light in May when it was posted on a Russian website.
A spokesperson for the Metropolitan Police said the man had been arrested for breaking the 1990 Computer Misuse Act.
PCs seized during the raids are now being forensically examined.
Police are continuing to investigate the theft of the core computer code that is run by key net hardware known as routers.
This hardware passes along the packets of data that everything sent across the net, such as e-mail, images, video and chat text, is split up into.
About 800 megabytes of Cisco's the Internetwork Operating System was posted on a Russian security website in May this year.
Some of the Cisco code was also posted to net chat channels.
The core code for this operating is as important to Cisco as the naked code of Windows is to Microsoft. The Internetwork software is used to power almost all Cisco's routers.
The code was quickly removed from the Russian website following complaints by Cisco.
Soon after the appearance of the code Cisco confirmed that the FBI was investigating how the theft had occurred.
Cisco said that it had not been stolen as a result of loopholes in its software.