A UK teenager has been arrested in a joint Scotland Yard and FBI probe into the hacking of websites.A man, named locally as Ryan Cleary, 19, has been arrested in Wickford, Essex. Police have not identified him.
On Monday the UK's Serious Organised Crime Agency (Soca) took its website offline after it was attacked by Lulz Security hackers.
Scotland Yard said the raid followed a series of distributed denial of service (DDoS) attacks.
But they would not confirm it was linked to LulzSec.
The raid in Essex had been a "pre-planned, intelligence-led" operation, said Scotland Yard.
The teenager was arrested under the Computer Misuse Act and Fraud Act and is being questioned at a central London police station.
He was arrested by the Metropolitan Police's e-crime unit.
- May 7: US X Factor contestant database
- May 10: Fox.com user passwords
- May 15: Database listing locations of UK cash machines
- May 23: Sonymusic Japan website
- May 30: US broadcaster PBS. Staff logon information
- June 2: Sonypictures.com user information
- June 3: Infragard website (FBI affiliated organisation)
- June 3: Nintendo.com
- June 10: Pron.com pornographic website
- June 13: Senate.gov - website of US Senate
- June 13: Bethesda software website. User information
- June 14: EVE Online, League of Legends, The Escapist and others
- June 20: Soca website taken offline
- June 21: National Census database reportedly attacked
A Scotland Yard spokesman said: "The arrest follows an investigation into network intrusions and distributed denial of service attacks against a number of international business and intelligence agencies by what is believed to be the same hacking group."Searches at a residential address in Wickford, Essex, following the arrest last night have led to the examination of a significant amount of material. These forensic examinations remain ongoing."
The teenager's mother spoke to BBC Radio Essex and confirmed her son had been arrested at 0330BST on Tuesday.
She said he had been obsessed with computers since he was 12 and added: "Computers were his world."
Scotland Yard is co-operating with the FBI as well as Essex Police.
An FBI spokesman said it had no comment "at this time".
Channel 4 News claimed LulzSec may have succeeded in hacking into the database of the 2011 Census, which holds details of every UK citizen who filled out the survey earlier this year.
But the Office for National Statistics has released a statement saying: "We are aware of the suggestion that Census data has been accessed. We are working with our security advisers and contractors to establish whether there is any substance to this.
"The 2011 Census placed the highest priority on maintaining the security of personal data. At this stage we have no evidence to suggest that such a compromise has taken place."
When Lulz Security, or LulzSec, first appeared in May, the group portrayed itself as a light-hearted organisation, bent on creating online fun and Lulz (laughs).But LulzSec is said to have been planning to establish itself as a rival to Anonymous, the hacking group embroiled in the WikiLeaks fallout.
LulzSec initially targeted US broadcasters PBS and Fox and gaming firms.
But the Twitter page @LulzSec then declared its intention to break into government websites and leak confidential documents.
LulzSec is also suspected of hacking into CIA, Sony and NHS websites.