McKinnon has admitted accessing the computers of US military headquarters the Pentagon and space agency NASA. The US won the right to extradite McKinnon in the High Court.
McKinnon said that when he was caught UK police told him that he would face a sentence no stiffer than community service. When US authorities sought his appeal, though, prosecutors in the US said that he could face up to 70 years in jail.
McKinnon has always argued that he should be tried, but in the UK where he performed his actions. He declined to take part in a controversial plea bargain with US authorities, and his legal team now claims that threats made about preventing him serving some of his sentence in the UK as part of the plea bargaining process breached his human rights.
The Administrative Court, part of the High Court, said in May that there were two questions of public importance which could form the basis of an appeal to the Lords.
The first is the status of a diplomatic note which said that McKinnon would not be treated as a terrorist. McKinnon said he had been told that he could be taken to Guantanemo Bay.
The second point relates to the behaviour of US authorities in conducting the plea bargaining negotiations.
McKinnon has previously told weekly technology law podcast OUT-LAW Radio that the charges brought against him by the US were manufactured to ease his extradition there.
"For it to be extraditable under their computer laws in America you have to have caused $5,000 worth of damage and lo and behold they say that every computer I was on I caused exactly $5,000 worth of damage so it is patently a falsely structured argument," McKinnon told OUT-LAW Radio last year.
McKinnon was searching for evidence of alien life and of the reverse-engineering of alien technology by the US military when he gained access to the computers. He says that he did see evidence of both.
He says that he used a very basic tool which scanned networks for blank passwords and found some very poor security. " When you look at the fact that my method for gaining entry was scanning for blank passwords, technically you could say that there was no security to begin with," he said.
