A London man described as the "world's biggest computer hacker" has been arrested.
Gary McKinnon, 39, was seized by the Met's extradition unit at his Wood Green home.
The unemployed former computer engineer is accused of causing the US government $1billion of damage by breaking into its most secure computers at the Pentagon and Nasa. He is likely to be extradited to America to face eight counts of computer crime in 14 states and could be jailed for 70 years.
The former Highgate Wood comprehensive-pupil was granted bail today at Bow Street Magistrates' Court.
Most of the alleged hacking took place in 2001 and 2002. At one stage the US thought it was the work of the al Qaeda terror network.
Friends said that he broke into the networks from his home computer to try to prove his theory that the US was covering up the existence of UFOs.
He is accused of a series of hacking offences including deleting "critical" files from military computers. The US authorities said the cost of tracking him down and correcting the alleged problems was more than £570,000. The offences could also see him fined up to £950,000 if found guilty on all charges.
He was arrested yesterday evening but the US first issued an indictment against him in November 2002.
Prosecutor Paul McNulty alleged that McKinnon, known online as "Solo," had perpetrated "the biggest hack of military computers ever". He was named as the chief suspect after a series of electronic break-ins occurred over 12 months at 92 separate US military and Nasa networks.
McKinnon was also accused of hacking into the networks of six private companies and organisations.