Gary McKinnon (Defendant) is an unemployed 42-year-old British citizen, who had considerable skill with his home computer in London. During the Spring of 2002, he used it to identify network computers of the U.S. Government, to copy the identities of certain administrative accounts and passwords, and to install unauthorised software which made it possible for him to access and change the data on those computers. He then deleted data from 97 computers, many of them high level U.S. military computers. The cost of repairs allegedly amounted to US $700,000.
The U.S. charged that the Defendant's conduct was intentional and calculated to influence the U.S. Government by intimidation and coercion. When interviewed under caution, the Defendant admitted responsibility but not that he had caused damage.
Before requesting the Defendant's formal extradition, the U.S. prosecutors informed the Defendant's legal representatives that, if Defendant went voluntarily to the U.S. without contesting extradition and if he pleaded guilty to two counts of "fraud and related activity in connection with computers," the prosecution would recommend to the court  that it sentence the Defendant for 3 to 4 years' imprisonment and,  that, after serving 6 to 12 months in the U.S. , the prosecutor would recommend to the Department of Justice that the Defendant serve the rest of his sentence in the United Kingdom, and  that the court and the department were likely to accept these recommendations. The Defendant was off ered a plea bargain on those terms.
His lawyers also told the Defendant that if he turned down this plan and the U. K extradited him to the U.S. and a jury convicted him on a not guilty plea, he could expect to receive a sentence of at least 8 to 10 years' imprisonment, possibly more and would serve the whole sentence in the U.S., probably in a high security prison. The Defendant refused the plea bargain offer and extradition proceedings began.
The English judge found that the Defendant's extradition to the U.S. would square with his rights under the U.K.-U.S. Extradition Treaty of January 21, 1977 [28 U.S.T.S 227; T.I.A.S. 8468; 1049 U.N.T.S 167 ] as supplemented by Treaty of December 23, 1986 [T.I.A.S. 12050; 1556 U.N.T.S. 369] and sent the case to the Secretary of State who ordered the Defendant's extradition.
The Defendant appealed on the ground that the wide disparity between the predicted likely outcome if he co-operated with the U.S...