Hacker Ryan Ackroyd, a.k.a "Kayla," recently halted a planned jury trial by pleading guilty to one count of computer hacking in London's Southwark Crown Court (h/t FT.com).
Ackroyd, along with fellow hackers Jake Davis, a.k.a "Topiary," Mustafa Al-Bassam, a.k.a. "Tflow," and Ryan Cleary, were members of the high-profile LulzSec hacker group, which targeted a wide range of organizations in 2011, including the CIA, PBS, News International and many others, before abruptly announcing the end of their 50-day campaign.
LulzSec member Hector Xavier Monsegur, a.k.a. "Sabu," became an FBI informant in 2011, leading to the arrest of Davis, Cleary, Ackroyd, Al-Bassam and others. Sabu has yet to be sentenced, due to his ongoing cooperation with the FBI.
Davis and Cleary pleaded guilty last June to some charges related to the attacks, though they denied involvement in leaking confidential data from targeted organizations. Al-Bassam, who recently turned 18, had not previously been publicly identified.
LulzSec's activities are documented in detail in Parmy Olson's excellent book, "We Are Anonymous."
The four will be sentenced on May 14, 2013.