Lawyers for a British computer hacker started an appeal in London High Court to block their client's extradition to the US.
Londoner, Gary McKinnon is accused of deleting data and illegally accessing information on 97 US military and NASA computers between February 2001 and March 2002. He's been charged in US District Court for the Eastern District of Virginia.
McKinnon, who did not show up in court, could face up to 60 years in prison, said his attorney, Edmund Lawson.
British authorities declined to prosecute McKinnon and the US sought to extradite him. He challenged the extradition order in Bow Street Magistrates Court in May 2006. His attorney contended that since US authorities allege McKinnon disrupted critical military networks after the 11 September 2001 US terrorist attacks, he could be held as an enemy combatant and subjected to inhuman treatment.
The judge rejected the argument and the UK Home Secretary John Reid subsequently approved an extradition order.
The appeal hearing will continue Wednesday in London High Court.
US authorities allege one of McKinnon's hacking sessions deleted files from computers at the US Naval Weapons Station Earle in New Jersey, causing the shutdown of 300 computers at a critical time.
McKinnon freely admits to hacking but contends he never damaged the targeted computers and merely did research on UFOs. He used a programme called "RemotelyAnywhere" to control other computers, accessing administrator accounts and gaining passwords, according to British court documents.
Most of his hacking occurred before office hours in the US. McKinnon's undoing came after he mistimed one of his probes, and a user cut McKinnon's connection after noticing the mouse pointer moving around on the screen.