A group of expert hackers who attacked governments and corporations around the globe has been busted after its ringleader one of the world's most-wanted and most-feared computer vandals turned against his comrades and secretly became an informant for the FBI months ago.
Five people, including a Chicago man, were charged in court papers unsealed in federal court in New York, and authorities revealed on Tuesday (local time) that a sixth person, Hector Xavier Monsegur, a legendary figure known in the hacking underworld as "Sabu," has pleaded guilty in New York, where he lives.
Authorities said it marked the first significant prosecution of major internet hackers.
According to court papers, members of the group got their start as part of a large worldwide hacking organisation known as Anonymous, which authorities said has been operating at least since 2008. Court papers accused Anonymous of a "deliberate campaign of online destruction, intimidation and criminality."
In chat rooms and on Twitter, Anonymous supporters erupted into a chorus of disappointment, confusion, and anger. Some wondered whether the news was an elaborate fraud. Others revisited earlier suspicions that Sabu was a government agent.
As members of Anonymous surveyed the damage, one of its most popular Twitter feeds assured its followers that it was still OK.
"We're sailing close to the wind," the feed read. "Our crew is complete and doing fine."
Monsegur was portrayed in court papers as the ringleader of some of the group's more infamous deeds. Authorities said he formed an elite hacking organisation last May a spinoff of Anonymous and named it "Lulz Security" or "LulzSec." "Lulz" is internet slang that can mean "laughs" or "amusement".
Despite the organisation's lighthearted name, authorities said Monsegur and his followers embarked on a dastardly stream of deeds against business and government entities in the US and around the world, resulting in the theft of confidential information, the defacing of websites and attacks that temporarily put victims out of business.
Authorities said their crimes affected nearly 1 million people.
Their exploits included attacks on cyber-security firms and the posting of a fake story that slain rapper Tupac Shakur was alive in New Zealand.
As their exploits became known, some hackers associated with the group boasted about their prowess.
Monsegur, free on US$50,000 bail, was charged with conspiracy to engage in computer hacking, among other offences. Authorities said he pleaded guilty August 15.
According to the court papers, he was an influential member of three hacking organisations Anonymous, Internet Feds and Lulz Security. Court papers said he acted as a "rooter," a hacker who identified vulnerabilities in computer systems.
The court papers said he participated in attacks over the past few years on Visa, MasterCard and PayPal; government computers in Tunisia, Algeria, Yemeni and Zimbabwe; Fox Broadcasting Co. and the Tribune Co; PBS; and the US Senate.
Also charged in court papers with conspiracy to commit computer hacking were Ryan Ackroyd, Jake Davis, Darren Martyn, Donncha O'Cearrbhail and Jeremy Hammond. Three were arrested on Tuesday; Davis and Martin were previously arrested.
Hammond, who is from Chicago, appeared before a federal judge there and was ordered transferred to New York. Martyn and O'Cearrbhail lived in Ireland, Ackroyd and Davis in Britain.
LulzSec members attained notoriety last May by attacking the PBS website and planting the false story about Shakur. According to court papers, Monsegur and others did it in retaliation for what they perceived to be unfavourable news coverage of Wikileaks on the PBS news program Frontline.
In July, when LulzSec's attacks were grabbing world headlines, an unknown person alleged that Sabu was Monsegur, publishing his personal details on the internet. Sabu took to Twitter to deny that he had been exposed, and as Anonymous's attacks continued, suspicions eased.
Barrett Brown, a former journalist who became closely associated with Anonymous, said Sabu's betrayal would have a serious effect on Anonymous.
"He was an admired Anon," he said. "He's been a leader. People came to him with information. God knows what else he told them."