Top members of the computer hacker group `` Anonymous '' and its offshoots were arrested and charged Tuesday after a wide-ranging investigation used the help of a group leader who was working as a secret government informant . Five of the suspects , considered by investigators among the `` most sophisticated hackers in the world , '' were arrested in the United States and Europe and charged in a Manhattan federal court over their alleged role in high-profile cyberattacks against government agencies and large companies , according to an indictment . A sixth man , Hector Xavier Monsegur , a notorious hacker known as `` Sabu , '' pleaded guilty in August to computer hacking and other crimes . As part of his plea deal , Monsegur cooperated with government investigators and helped build a case against the five other defendants , according to a source with knowledge of the investigation . Ryan Ackroyd , 23 ; Jake Davis , 29 ; Darren Martyn , 25 ; and Donncha O'Cearrbhail , 19 , have been charged with conspiracy regarding attacks against Fox Broadcasting Co. , Sony Pictures Entertainment and the Public Broadcasting Service , or PBS . O'Cearrbhail is also accused of hacking into the personal e-mail account of an Irish national police officer and eavesdropping on a conference call between Irish police , the FBI and other law enforcement agencies about ongoing investigations into Anonymous and other hacker groups . The suspect allegedly recorded the call and disseminated the recording to other hackers . Jeremy Hammond , 27 , was charged with a December cyberattack against a Texas firm called Strategic Forecasting Inc. , which authorities say might have affected about 860,000 people . O'Cearrbhail and Martyn are from Ireland , and Hammond is from Chicago , the indictment said . Ackroyd and Davis are from Britain . Monsegur , 28 , in August pleaded guilty to 12 counts of computer hacking and other crimes . Known as a `` rooter , '' the New York City resident identified vulnerabilities in a variety of computer systems and then passed along that information to other hackers . Monsegur and others have claimed responsibility for cyberstrikes between December 2010 and June 2011 that included denial of service attacks against the websites of Visa , MasterCard and PayPal . A denial of service ( DoS ) attack typically involves the use of a large number of computers to bombard websites with phony requests for information , causing the site to temporarily shut down . Dubbed `` Operation Payback , '' authorities say the credit card and PayPal attacks were prompted by the firms ' refusals to process donations to WikiLeaks , an organization that facilitates the anonymous leaking of secret information . The group 's website has released thousands of classified diplomatic cables as well as confidential -- and , at times , controversial -- messages about the wars in Iraq and Afghanistan . Authorities say Monsegur also hacked or launched DoS attacks against computer systems operated by the governments of Tunisia , Yemen , Algeria and Zimbabwe . Beginning in December 2010 , the indictment said , Monsegur , Ackroyd , Davis , Martyn and O'Cearrbhail conspired as a splinter hacker group called Internet Feds and penetrated the website of Fine Gael , an Irish political party , as well as the computer systems of a security firm called HBGary Inc. and its affiliates . The group allegedly stole confidential data from about 80,000 user accounts associated with the firm . Then in 2011 , apparently feeling the heat from investigators , the group formed another offshoot organization called Lulz Security , or LulzSec , the indictment said . LulzSec then ratcheted up `` a campaign of malicious cyberassaults on the websites and computer systems of various business and governmental entities in the United States and throughout the world . '' Barrett Brown , who identifies as an Anonymous spokesman , told CNN that Sabu recently took over leadership of LulzSec . He said the hacker also contacted him several months ago by instant message , and he described those communications as `` weird . '' `` There have always been rumors from a couple of people ( within Anonymous ) something weird was going on with LulzSec when ( Sabu ) started , '' said Brown , whose Dallas apartment was visited by FBI agents early Tuesday morning . Brown said that he and others in Anonymous were upset with LulzSec and Sabu because Sabu had bragged about stealing credit card information . Still , he says , Tuesday 's indictments wo n't disrupt the organization 's actions over the long-term . `` There are more than enough people around , '' he said . `` Major operations going forward wo n't be interrupted . Authorities have said that leader within the organization was secretly working with government officials and aided their investigation . Anonymous is considered a loosely tied group of hackers , that have spawned affiliate bodies , and in recent years have focused their efforts on coordinating cyberattacks for political reasons or as retribution for the activities of governments and large corporations .
5 alleged hackers in the U.S. and Europe have been charged in Manhattan court . A sixth has pleaded guilty to computer hacking and other crimes . They are suspected to be top members of `` Anonymous '' and splinter groups . Groups called Internet Feds , AntiSec , LulzSec claimed responsibility for cyberattacks .