The FBI has brought charges against six young men suspected of being leading lights in the loose network known as Anonymous, who are accused of having "waged a deliberate campaign of online destruction, intimidation and criminality".
As alleged members of smaller hacking groups called LulzSec, Internet Feds and AntiSec, they are said to have been behind cyber attacks on the websites of major companies and world governments and the theft of confidential data.
Among the accused named in New York federal court documents as taking part in "computer hacking conspiarcy" are a 19 year-old from the Shetland islands, Jake Davis, and a 25 year-old from Doncaster, Ryan Ackroyd. They have already been arrested by British police but now face possible extradition to the US.
One of two Irish men facing charges, Donncha O'Cearrbhail, is accused of hacking a confidential conference call between the FBI and the Metropolitan Police in January and then releasing it onto the internet, in an incident that caused huge embarrassment to the authorities.
A sixth man, Jeremy Hammond of Chicago, is said to have been responsible for a hack of the Stratfor intelligence firm's website that "affected approximately 860,000 victims". Millions of sensitive emails were published after finding their way to the whistleblowing group WikiLeaks.
The charges, detailed in a 24-page indictment released on Tuesday, were brought after Hector Xavier Monsegur, alleged head of the elite LulzSec group, agreed to cooperate with the FBI in return for lesser charges.
Court documents reveal that Mr Monsegur, a 28 year-old from New York known as Sabu, secretly pleaded guilty to computer hacking conspiracy charges in August last year and began providing information to the FBI's investigation.
In a 24-page charge sheet, New York prosecutors accuse the six men of attacking websites ranging from an Irish political party to MasterCard and of stealing information from 70,000 potential contestants on the American X-Factor.
Mr Ackroyd, said to be known online as Kayla and Lolspoon, is accused of helping to identify weaknesses in targets' computer systems and breaking down their security to gain confidential information while Davis, who allegedly used the handle Topiary, is alleged to have used to have used Twitter to boast of the group's exploits and to have helped store stolen data.
Both are both charged with two counts of conspiracy to hack computers and under American law could face a maximum of 20 years in prison.
The US is known to aggressively pursue the extradition of alleged hackers and is currently seeking to bring Gary Mackinnon, a 46-year-old from Glasgow, into American jurisdiction to face charges of computers belonging to Nasa and the Pentagon.
The Home Office said it could not "confirm or deny" if an extradition request had been made.