An autistic computer hacker who faces extradition to America over allegations that he stole huge amounts of data from government agencies warned he would kill himself if he was sent to the US.
Lauri Love, who has Asperger Syndrome, said the "deck" was "stacked" against him because the American justice system "coerces" accused people into pleading guilty to get reduced sentences.
The 31-year-old, who lives with his parents in Suffolk, said he doubted there was "any prospect" of him having justice if he was sent to the US.
And Mr Love, who also suffers from severe eczema, suggested that the inevitable ignoring of his physical and mental disabilities in American jails would push him to suicide.
He said: "If I was sent to America under horrific conditions those urges to bring my life to an end would be a lot stronger.
"Sadly what I expect will happen - the urges, the despair, the helplessness, the hopelessness - I will exercise what remains of my self-control and I will take my life.
"(Extradition) will result in a tragedy that could be avoided by not having me kidnapped."
Mr Love is accused of hacking into the US Federal Reserve, the Department of Defence, Nasa and the FBI in a spate of online attacks in 2012 and 2013.
Authorities there want him to stand trial in three different jurisdictions - New York, New Jersey and Virginia - over charges of cyber-hacking, which his lawyers say could lead to him spend up to 99 years in prison if found guilty.
On the first day of his extradition hearing, Westminster Magistrates' Court was told lengthy legal proceedings in the US and the potential of decades in jail could cause his health to deteriorate and lead to mental breakdown, with suicide a "high risk".
Mr Love arrived at the court on Wednesday wearing an origami rose he had crafted while in the dock the previous day.
Giving evidence as his friends and supporters watched on from the public gallery, his parents listening intently at the back of the court, Mr Love spoke of his fears of the prospect of facing the US justice system.
Scratching his back and head uncontrollably in the witness stand, he said the extradition agreement between the UK and US was based on "mutual judicial trust".
But he said: "96% or 97% of cases end in a plea. Under a system with less coercive plea bargaining they would be found innocent."
Mr Love said he expected it would take five years before his case came to trial, and that he faced three prosecutions in three different jurisdictions.
He said: "The deck is stacked for most people, that is why we have 19 out of 20 cases not going to trial ...
"I do not entertain any prospect of having justice in the US. If I have justice it will be here in the UK."
Outlining his fears of abuse - the availability of uncontrolled drugs, extreme violence and the high rates of suicide in US prisons, particularly among people with mental health disabilities - he added: "Being in prison in the US, I can't imagine anything worse for me."
Representing the US authorities, Peter Caldwell suggested Mr Love and his family had courted the media over his case.
He put it to him that he and his supporters had crafted a media strategy and "consciously sought to garner support against your extradition".
Mr Caldwell told him: "You sought to propagate it, encourage it."
But Mr Love said it was only right that the media play a role in such cases and said people were interested in the "right thing happening".
Mr Caldwell also suggested Mr Love tried to "put yourself in the imprint" of Gary McKinnon, another alleged cyber-hacker with Asperger's who was spared extradition after a decade-long fight following intervention from the Home Secretary.
And he accused Mr Love of dramatising what he said was a "manageable condition" to avoid being sent to America, saying: "My suggestion to you is you seek to promote your personal difficulties as a shield to avoid your extradition."
When Mr Caldwell suggested that his diagnosis of Aspergers - which occurred after extradition proceedings started - "might affect your situation positively", Mr Love told him: "It is up to you if you want to call into question the veracity of medical experts.
"If the thrust of the argument is that we collaborated to create misleading medical reports that is disappointing."
And when Mr Caldwell questioned the way he had dealt with his diagnosis, Mr Lord asked him: "What is your medical advice?"
Earlier in the hearing on Wednesday, Mr Love spoke of the "despondency" his undiagnosed health problems brought him as a child, saying "there wouldn't be a year in my life where I wouldn't have an episode" of depression.
But he said he was "unwilling to burden others" with his problems.
Mr Love became choked up and held back tears as he told the court how he launched into hacktivism following the 2013 death of "wunderkind" Aaron Swartz, an internet pioneer who hanged himself after being accused by US authorities of wire fraud when he set up a system to download academic journals at MIT.
He said: "We are all invested in making a better world for each other. Sometimes that involves confrontational situations with people in power."
The court heard that Mr Love now works with "ethical hacking" and security organisation My Hacker House, which advises organisations on cyber-security, helps teach youngsters online skills and has received the backing from the Duke of York for its scheme of awarding cyber badges to children.
Jenny Arcuri, chief executive of My Hacker House, told the court: "Everything about Lauri's work ethic is drawn to the social good and giving back."
And Mr Love told the court himself: "I do want to be in a position that the talents I have are most effectively applied to making this world a better place.
"There are a certain class of people who are uniquely positioned to help us through this period (of increasingly technological integration in the world).
"Those are the hackers. We can continue to criminalise... or their talents can be put towards saving us."