Five hackers associated with some of the most notorious cyber-crimes in recent years were charged Tuesday after a key member of their loose network was turned by the FBI and became a confidential informant, federal officials said.
Federal prosecutors in New York unveiled charges against five men -- two from Britain, two from Ireland and one from Chicago -- in connection with a string of cyber-assaults in which hackers stole confidential information from U.S. companies and temporarily shut down government Web sites.
In one of the most recent cases, the hackers are alleged to have provided e-mails from Stratfor, a private intelligence firm with close U.S. government ties, to the anti-secrecy group WikiLeaks, which in February began publishing them online.
Officials said Tuesday that investigators were led to the five men, affiliated with the hacking group Anonymous, by Hector Xavier Monsegur, a New York-based hacker arrested last June who began secretly working with the FBI to identify some of his cohorts.
"This is the most important roll-up of hackers ever," said cybersecurity analyst Richard Stiennon, who has closely followed Anonymous. He said the investigation has injected "distrust into Anonymous" and the FBI may have "broken the back of the collective."
The men were indicted on computer-hacking charges and other crimes by the U.S. Attorney's Office for the Southern District of New York. It was unclear how many of the European suspects had been arrested.
Still, senior law enforcement officials said the case will take "core members" offline, and that more charges could follow.
A second official said Mr. Monsegur, who lives in public housing on Manhattan's Lower East Side, was identified after an apparent slip-up in which he did not mask his Internet protocol address while he was online. Officials said the prospect of a long prison sentence convinced him to cooperate with the FBI.
Mr. Monsegur, known online by the handle Sabu, had 45,000 Twitter followers.
Before his arrest, made public Tuesday, Mr. Monsegur briefly participated in retaliatory attacks on the Web sites of Visa, MasterCard and PayPal after those organizations stopped processing transactions for WikiLeaks.
Among those arrested Tuesday was Jeremy Hammond of Chicago, accused of breaking into the computer systems of Austin-based Stratfor.
The other men charged Tuesday were identified as Donncha O'Cearrbhail of Birr, Ireland; Ryan Ackroyd of Doncaster, England; Jake Davis of the Shetland Islands, Scotland; and Darren Martyn of Galway, Ireland.
First Published March 7, 2012 5:00 AM