After hacking into the CIA, Sony, PayPal and Mastercard Web sites over the years, Sabu, suspected leader of Anonymous splinter group LulzSec pled guilty to 12 counts of conspiracy to engage in computer hacking March 6. Five other suspected hackers were also arrested March 6, and it now looks as if Sabu, also known as Hector Xavier Monsegur, had been cooperating with the FBI since the middle of 2011, according to papers filed in a Manhattan court.

The story of how a notorious computer hacker could have possibly been working with the federal government for so long was broken by Fox News. Word spread rapidly about possibly the most notorious computer hacker in the world, and now arrests in the UK, Ireland and Chicago show the group is all but finished. It turns out Monsegur had mistakenly logged into an Internet relay chatroom without first setting up a proxy server. This was all federal agents needed to zero in on his IP address, Fox News reported. From there, it was easy enough for agents to get Monsegur to work with them. They just had to threaten to take away his two children and throw him in jail.

LulzSec grew out of the Anonymous collective at the beginning of 2011, but a June 2011 attack on FBI affiliate InfraGard may have been the turning point for Sabu's downfall. LulzSec had taken credit for the attack by saying it was in response to the Pentagon's consideration of passing a policy to classify some online hacks as acts of war, the The Guardian UK reported at the time. Monsegur has been described in the Fox News report as an unemployed 28-year-old New York City resident who had been living on public assistance with his two children.