Two men have been charged in the UK in connection with hacking attacks from Anonymous and LulzSec, and a further two have been arrested - one of whom may be one of LulzSec's most active members.
The two men, aged 24 and 20, were arrested in South Yorkshire and Wiltshire and charged with conspiring to commit offences under the Computer Misuse Act 1990. Computer equipment was seized from the Doncaster address.
"The arrests relate to our enquiries into a series of serious computer intrusions and online denial-of-service attacks recently suffered by a number of multi-national companies, public institutions and government and law enforcement agencies in Great Britain and the United States," says DI Mark Raymond of the Metropolitan Police Service's Central e-Crime Unit.
"We are working to detect and bring before the courts those responsible for these offences, to disrupt such groups, and to deter others thinking of participating in this type of criminal activity."
According to Scotland Yard, the arrests relate to the activities of one of LulzSec's most prominent members, Kayla - although Kayla presents him or herself as a teenage girl.
Certainly, Kayla's Twitter account has been silent since the time of the arrests.
Separately, two men were charged yesterday over online attacks by Anonymous.
Christopher Weatherhead, 20, from Northampton, and Ashley Rhodes, 26, from south London, have been charged with conspiracy to carry out an unauthorised act in relation to a computer.
Two other young men were previously charged in relation to the same offences, and aall four will appear before the City of Westminster Magistrates Court on September 7.