More than a dozen people were arrested yesterday as part of an investigation into the activist hacking group Anonymous.
The detainment of at least 14 individuals come just a day after the group released email addresses and passwords it claims belonged to a host of senior News International executives, including former chief executive Rebekah Brooks.
The group had previously alleged to have broken into Apple servers and launched attacks which shut down MasterCard sites.
Arrests were made in California, Florida and New Jersey, following raids on six locations in New York, including one in Brooklyn and five others on Long Island. They were searched for computers and computer-related accessories.
The equipment was suspected of being used by members of the grass-roots organisation inspired by WikiLeaks and its founder Julian Assange.
FBI officials in California and Florida said searches were under way but declined to confirm any arrests. A spokesman for the FBI in New Jersey said one arrest was made there but declined to say where or on what charges.