Photo: JEAN-PHILIPPE KSIAZEK/2012 AFP

A splinter group of the hacker collective Anonymous has been brought down by the FBI with the help of its leader, a New Yorker called Sabu, Fox News reports. Born Hector Xavier Monsegur, the 28-year-old is as close as the crew has to a star, having led high-profile attacks and commanding the Anonymous spin-off LulzSec. Three suspected LulzSec hackers have been arrested, Reuters reports, with charges coming against two more. “This is devastating to the organization,” an FBI source told Fox, clearly gloating after having their phone call hacked by the group, among other inconveniences in the ongoing battle. “We’re chopping off the head of LulzSec.”

Sabu, a father of two, was reportedly unemployed and hacking from a public housing project on the Lower East Side until he was arrested by the FBI last June. He pleaded guilty to twelve hacking charges in August, and has been cooperating with law enforcement since, according to Fox. “He’s extremely intelligent,” said an official. “Brilliant, but lazy.” They caught him logging into a chat room without blocking his IP address, and he later agreed to help the FBI “because of his kids,” an agent said. “He’d do anything for his kids. He didn’t want to go away to prison and leave them. That’s how we got him.”

In August, Gizmodo spoke to another prominent hacker who questioned Sabu’s disappearance that summer. A raid on Anonymous followed, raising more suspicions about Sabu’s loyalty. But he’s continued to be a public face for the movement, tweeting to his 45,000+ followers just yesterday, “The federal government is run by a bunch of fucking cowards. Don’t give in to these people. Fight back. Stay strong.”

Another Anonymous mouthpiece is already working some spin: “Never forget: We are Legion,” tweeted @YourAnonNews. “We do not have a leader nor will we ever. #Anonymous –> The best #idea on Earth.” But as one expert said recently, “Anonymous is a handful of geniuses surrounded by a legion of idiots. You have four or five guys who really know what they’re doing and are able to pull off some of the more serious hacks … ” Sabu was supposed to be one of those guys.

Update: Court documents on Sabu can be seen here. In the papers, he’s charged with involvement in hacks on Visa, MasterCard, and PayPal (in solidarity with Wikileaks), as well as the governments of Yemen, Tunisia, Algeria, and Zimbabwe. Also mentioned are attacks on Internet security firm HBGary, Fox, the Tribune Company, PBS, Sony, the U.S. Senate, and more.

Barrett Brown, a writer and activist often referred to as an Anonymous spokesman, tweeted this morning, “My apartment was raided this morning by the FBI. Feds also came to another residence where I actually was. Sabu is a traitor.” He said he wasn’t arrested — “They wanted laptops.”