It didn't take much time to turn Hector "Sabu" Monsegur into an FBI informant—just a few hours, in fact. “Since literally the day he was arrested, the defendant has been cooperating with the government proactively,” Assistant US Attorney James Pastore told a federal judge last August.

Monsegur had been a key member of Anonymous and later the “happy hackers” of LulzSec, a spinoff group that broke into servers around the world during the summer of 2011 and taunted the FBI about it. But the moment that Monsegur was arrested at his public housing apartment in June, his life took a dramatic turn.

"The defendant has literally worked around the clock with federal agents,” Pastore continued. “He has been staying up sometimes all night engaging in conversations with co-conspirators that are helping the government to build cases against those co-conspirators.”

When the Monsegur documents were unsealed in early March 2012, I contacted the Southern District Court Reporters in lower Manhattan to purchase a transcript of his two hearings from summer 2011, one from August 5 and the second from August 15. They sent back only the August 15 transcript, which was the hearing at which Monsegur pled guilty; a follow-up message elicited no response.

But I recently got my hands on the August 5 transcript and, though of limited interest, it does contain several passages that shed light on Monsegur's lifestyle between June and August last year. Not only did Monsegur turn almost immediately, but he worked hard for the feds in all-night sessions. He couldn't afford to slack off, of course; his cooperation was closely monitored and Monsegur was taking care of two small children who would be separated from him if he were hauled off to jail instead.

Here's how the government described its work with Monsegur:

We have installed software on a computer that tracks his online activity. There is also video surveillance in the defendant's residence. So, all of his activities have been closely monitored, which has obviously been an imposition not only on him but he also has two daughters that he takes care of—is the foster parent for them. The results of this carefully monitored cooperation have already been quite positive. To give the court some sense of it, the defendant receives information about security vulnerabilities from a network, literally a worldwide network of criminals, cybercriminals. On a day-to-day basis the defendant can sometimes receive upwards of two dozen vulnerabilities. Working with the FBI, that information has been used to patch more than 150 vulnerabilities to date. When I say “patch,” I mean the FBI has been able to reach out to victims sometimes before the hack has actually occurred, other times after the hack has occurred but in an effort to mitigate the harm from that hack. That is, frankly, something that we would probably not have been in a position to do without the defendant's cooperation. The defendant's information is also helping the government close in on several prominent cybercriminals.

Apart from the fact that government lawyers love the words “literally” and “cyber,” the main takeaway here is that that the hacker who taunted the feds about their inability to find him was (literally) on video and computer surveillance by those he taunted—24 hours a day.

Revenge

Monsegur's state of mind at the time is impossible to discern, but the government noted just how important it was to keep his activities a secret. Anonymous and LulzSec hackers were known to retaliate by "ordering hundreds of pizzas to someone's house" or "calling in hostage situations in part by using family information and having a SWAT team show up at that person's home. It's actually called 'swatting.'" Monsegur had already "incurred a significant amount of personal risk by deciding to cooperate."

While Monsegur's work wasn't enough to prevent the hacks of companies like Stratfor in December 2011, it apparently derailed many others. And it was crucial in the international spate of early March arrests that brought in most of the core LulzSec crew.

As for Monsegur, his own fate isn't yet known. His court case continues, and Monsegur has remained out of sight, no doubt hoping to avoid a flood of pizzas—or worse.