The British hacker accused of cracking Pentagon security will take his fight against extradition to the Law Lords today.
Gary McKinnon stands accused of penetrating the defences of 97 US military and NASA systems, leaving messages to be found by investigators.
McKinnon claimed the attacks were simply acts of curiosity, however the US alleges he not only damaged equipment, but stole sensitive files which could be useful to the enemies of the US.
McKinnon's lawyers claim an extradition could see their client jailed for anything up to 45 years, without any possibility of serving part of his sentence in the UK.
They are arguing that extradition be denied by the Law Lords on the grounds that their client has been subjected to "improper threats", notably an interview at the US embassy, in which he was reportedly told that if he went to the US and pleaded guilty he would be granted a minimum sentence and repatriated, but otherwise could expect to serve a full sentence in the US.
They also allege McKinnon was threatened by a New Jersey prosecutors who claimed he "would fry".
McKinnon appealed the extradition in the High Court in 2007, however, the presiding judges said they could find no grounds for appeal.
