Computer hacker Gary McKinnon has won his 10-year fight against extradition after Home Secretary Theresa May stepped in to halt proceedings.
Mrs May stopped his extradition on human rights ground after medical reports showed the 46-year-old was very likely to try to kill himself if extradited.
Ten years ago, from his north London bedroom McKinnon hacked into the Pentagon's computers. He was accused by US prosecutors of "the biggest military computer hack of all time", but he claims he was simply looking for evidence of UFOs.
Simon Harris reports.
Mrs May said the sole issue she was considering was whether "extradition to the United States would breach his human rights".
There was no doubt McKinnon is "seriously ill" and the extradition warrant against him should be withdrawn, she said.
His mother said she wanted to thank the Home Secretary from the bottom of her heart.
It is now for the director of public prosecutions Keir Starmer QC to decide whether he should face trial in the UK, Mrs May added.
Before the Home Secretary's decision, McKinnon's mother, Janis Sharp, said she was optimistic that the government would decide against extradition.
He's had high profile support. David Cameron supported Gary while he was Leader of the Opposition. He's also had the constant of his mother campaigning to keep him here.
The last few years, Ms Sharp says, have been torture for Gary - a "waterboarding of the mind".
She had said she believed that extraditing her son to the USA would prove a "death sentence" as he is at a high risk of suicide.
Gary McKinnon's local MP had also warned that the Home Secretary would have "blood on her hands" if she approved his extradition to the USA.
David Burrowes, the Conservative MP for Enfield South, had threatened to resign from his position as a ministerial aide to the Environment Secretary if the extradition goes ahead.
Click here to watch a clip of him talking to ITV Daybreak.
Mr McKinnon, who has Asperger's syndrome, is accused of hacking into 97 American military computers at the Pentagon and NASA.
He has never denied accessing US military computers but claims he was looking for evidence of UFOs, which he is passionately interested in.