A hacker broke into the US network of mobile phone company T-Mobile and accessed details of around 400 customers – including those of a Secret Service agent who investigates internet identity thieves.

California's Nicholas Lee Jacobsen, 21, was arrested as part of a Secret Service internet fraud crackdown called Operation Firewall.

Security Focus has a comprehensive report about Jacobsen's year-long access to the T-Mobile network – and on how the Secret Service "played the dual role of investigator and victim in the drama".

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