British LulzSec 'hactivists' caused websites to crash across the world for their own amusement

Working from their bedrooms, they stole personal data from hundreds of thousands of people

The LulzSec logo and Ackroyd (top-left), Al-Bassam (top right), Davis (bottom left) and Cleary. (PA and Getty)

Four "modern day pirates" launched cyber-attacks on the CIA and global corporations stealing huge amounts of sensitive data and causing websites to crash across the world for their own amusement, a court heard today.

The British computer hackers, belonging to a collective known as LulzSec, targeted News International, Sony, Nintendo and the FBI among other high profile victims in a series of sophisticated raids mounted from their bedroom computers.

Southwark Crown Court was told that Ryan Ackroyd, Jake Davis, Mustafa Al-Bassam and Ryan Cleary considered themselves to be "hacktivists", stealing vast quantities of personal information including passwords and credit card details as they penetrated the firewalls of some of the world's leading organisations.

They then posted the information on the LulzSec website and file-sharing sites.

Prosecutor Sandip Patel said the men - who pleaded guilty to a number of charges relating to unauthorised computer activity - were not motivated by politics such as international hacking group Anonymous but rather sought the attention their computer skills conferred on them.

"It's clear from the evidence that they intended to achieve extensive national and international notoriety and publicity," he said. "They saw themselves as latter-day pirates."

He added: "This is not about young immature men messing about. They are at the cutting edge of a contemporary and emerging species of criminal offender known as a cyber-criminal."

The organisation took its name from Lulz, which is internet slang for "laughs" and Sec referring to "security". LulzSec - whose motto was "We are legion. We do not forgive. We do not forget. Expect us" - only existed for a few months in 2011 building up a massive international following including 355,000 Twitter followers.

Many made donations using the Bitcoin online currency system. But LulzSec officially disbanded in June announcing its decision with an internet message. The four men were all arrested by September, the court heard.

In one security breach alone it was alleged Sony lost details relating to 26.4m customers. The FBI and the CIA websites were crashed in orchestrated attacks including one called "Wipeout Wednesday".

Some of the onslaughts were carried out with other unknown hackers from groups said to include Anonymous and Internet Feds by using a remotely controlled network of up to one million "zombie" computers - hijacked without the knowledge of their owners.

Ackroyd, 26, from Mexborough, South Yorkshire, used the online persona of a 16-year-old girl called Kayla, pleaded guilty to one charge of carrying out an unauthorised act to impair the operation of a computer.

The court was told the former soldier had hacked into News International diverting readers of the Sun's website to a fake story about Rupert Murdoch committing suicide.

Al-Bassam, 18, from Peckham, south London, was still at school and used the alias tFlow, whilst Davis, 20, originally from Lerwick, Shetland, was alleged to be in charge of the group's media relations and went by the name of Topiary. Both previously pleaded guilty to hacking and launching cyber-attacks on a range of organisations, including the Serious Organised Crime Agency.

Cleary, 21, of Wickford, Essex, also known as ViraL, pleaded guilty to the same two charges as well as four separate charges including hacking into US air force computers at the Pentagon.

He also admitted possession of indecent images relating to child abuse. Cleary, who suffers from Asperger's Syndrome is alleged to have set up the zombie network for the three core members.

He was described as a "totally obsessed compulsive individual" who had been excluded from a series of schools and was living as a virtual recluse. Davis, who is facing possible extradition to the US, was said to have turned his life around and was working with arts organisations in London.

The hearing was adjourned until tomorrow.