Infamous LulzSec hacking group leader Sabu has been cooperating with the FBI for several months as part of an investigation that has resulted in a number of arrests both sides of the Atlantic.
Sabu was unmasked as 28-year-old unemployed New Yorker hector Xavier Monsegur and reports have suggested that he has been cooperating with the US authorities since June. If so Sabu had apparently been 'turned' even before the supposed Lulzsec "Topiary" Jake Davis was arrested in the UK in July.
Looking back, at the time when Topiary was posting a string of defiantly self-important messages on Twitter, authorities worldwide had already closed in the leader and based on his information, were busy tracking down a number of other hackers.
Lulzsec's brief but active period saw the hacking group target a number of websites belonging to high profile companies such as Sony, PBS and Fox. The group posted stolen information including user account details.
The FBI subpoenaed the Facebook account of Sabu, revealing messages in which he sold stolen credit cards to other hackers. That provided enough evidence for the FBI to charge Monsegur with a variety of offenses which apparently delivered all the incentive Monsegur needed to begin cooperating.