Seven alleged hackers based in the US, UK and Republic of Ireland have been charged with crimes related to computer attacks said to have affected "over one million victims".
The FBI said that five of the men were involved in the group Lulzsec, while a sixth was a "member" of Antisec.
It said that Lulzsec's "leader" Hector Xavier Monsegur had pleaded guilty in August to 12 criminal charges.
The BBC understands Mr Monsegur subsequently co-operated with the FBI.
It is believed that this action helped lead to the other accusations.
The bureau said that Mr Monsegur - also known as Sabu - had admitted involvement in cyber attacks against the media groups Sony Pictures Entertainment, Fox Broadcasting Company and the Public Broadcasting Service (PBS) among others.
It said that Jake Davis, 19, from Lerwick, Shetland Islands; Ryan Ackroyd, 25, from Doncaster; and Darren Martyn, 25, from Galway, Ireland have also been charged with two counts of computer hacking conspiracy.
Donncha O'Cearrbhail, 19, from Birr, Ireland, faces one count of computer hacking conspiracy and a separate allegation that he disclosed an unlawfully intercepted data feed. The Irish police said they had arrested a male suspect in connection with the crackdown.
Scotland Yard said an unnamed 17 year-old from south London had also been charged with two counts of computer hacking.
The FBI added that Jeremy Hammond - nicknamed Anarchaos - had been arrested in Chicago on Monday in connection with the attack on the Stratfor security think tank carried out in December. It is alleged that the Antisec movement subsequently published stolen material to a file sharing website.
'Internal rift'
According to the court papers Mr Monsegur formed Lulzsec last May. It said he acted as a "rooter", identifying vulnerabilities in victim's computer systems.
Alongside other recruited hackers he is also alleged to have attacked the US Senate, the cyber security firm Unveillance, Visa, Mastercard and Paypal.
The FBI said he faced a maximum sentence of more than 124 years in prison if found guilty of all counts.
Prof Alan Woodward, from the University of Surrey's department of computing noted that other hackers appeared to have felt betrayed following reports that Mr Monsegur had aided law enforcement offices with the other arrests.
"The hacker group Lulzsec have been relatively quiet since the middle of 2011 which matches with what is being reported about when the leader of this group was arrested," he said.
"Judging by the level of activity this morning, where hackers have been pasting personal information about the person reported as having turned witness to implicate other hackers, it would appear that there is a considerable rift inside these groups."
Trend Micro's director of security research, Rik Ferguson, added that while this might mark the end of Lulzsec, it would be premature to say the same about Anonymous.
"Anonymous is a very different organisation to Lulzsec and other more closely linked groups - anyone can and does act in the name of Anonymous and their activities do not require individual hacker publicity or disclosure of personally identifiable details," he said.
"The very fact that Sabu became the 'celebrity' he was, illustrates the real difference between Lulzsec and Anonymous.
"I think the hackers we really need to worry about are those that trusted no-one and sought no glory in the first place."
A tweet posted by AnonymousIRC - which identifies itself as the "Antisec embassy" - said: "We're sailing close to the wind, our crew is complete and doing fine."
