The FBI raided six locations in New York and conducted searches in California on Tuesday as part of an investigation of the Internet vigilante hacking group Anonymous, agency officials said.
One residence in Brooklyn and five others on Long Island were searched for computers and computer-related accessories suspected of being used by members of the grass-roots organization inspired by WikiLeaks and its founder Julian Assange, FBI spokesman Peter Donald in New York said.
Another FBI spokesman, Tim Flannelly, said the searches in New York were in relation to an ongoing investigation of Anonymous.
At least one laptop was removed from one home. No arrests were made in New York.
An FBI spokeswoman in California said law enforcement actions were conducted in the San Francisco Bay Area but declined to say if any arrests were made.
Anonymous claimed to have broken into Apple Inc servers earlier this month. It also launched attacks in December that temporarily shut down sites of MasterCard Inc and Visa Inc using simple software tools freely available over the Internet.
Anonymous, which the FBI believes is mostly made up of hackers believed to be in their teens and early 20s, also has released scores of private e-mails and other data from an Arizona police website.
The group teamed up with the Lulz Security group of hackers in June. LulzSec has breached websites of Sony Corp, the CIA and a British police unit.
Experts say the FBI raids should have been expected as the group's actions have become more daring.
I don't think anybody should be surprised, said Josh Shaul, chief technical officer of Application Security, Inc., which helps companies protect their data. They played with fire and they got burned.
(Reporting by Basil Katz and Christine Kearney in New York, Dan Levine in San Francisco, Diane Bartz in Washington)