The FBI has seized a server in Texas as part of its hunt for the groups behind the pro-WikiLeaks denial-of-service attacks launched in December against PayPal, Visa, MasterCard, and others, according to a report.

During a December 16 raid, agents seized a server at Tailor Made Services, a Dallas-based co-location, or server-hosting, facility, and copied two of its hard drives, according to The Smoking Gun Web site, which said it has obtained the FBI affidavit in support of a search warrant for the seizure.

It's not clear what was found on the drives, The Smoking Gun reported, saying that search warrant records showed agents were authorized to seize material related to the attacks or to other illegal activities involving the groups Anonymous or 4chan.

Anonymous has claimed responsibility for deluging the Web sites of PayPal and others with data in order to bring the sites down. The attacks, the group says, were a response to actions taken by the site holders against WikiLeaks, after WikiLeaks publicly released a slew of confidential U.S. diplomatic cables. PayPal, MasterCard, and Visa all decided to prevent WikiLeaks from collecting donations via their financial networks. 4Chan has said it was behind an attack to shut down the sites for Swiss bank PostFinance and lawyers in Sweden prosecuting sex allegations against WikiLeaks front man Julian Assange.

The FBI began its probe after PayPal contacted the agency, The Smoking Gun reported, and the Internet payment company subsequently provided the bureau with eight IP addresses it said were associated with the attacks. The FBI's investigation has focused on tracing at least two of those addresses--one that's led the agency through Germany and France before taking it to Texas, and another that's led, through Canada, to Hurricane Electric, a hosting company near San Jose, Calif., The Smoking Gun reported.

The Smoking Gun said it had not received a response to a request for comment from Hurricane Electric. It also said that during a phone interview, the FBI agent who filed the affidavit declined to provide additional information.

Both the German Federal Criminal Police and the Royal Canadian Mounted Police have been involved in the investigation, The Smoking Gun said, adding that U.S. investigators claim the attacks are felony violations of a federal law covering the "unauthorized and knowing transmission of code or commands resulting in intentional damage to a protected computer system."