The FBI has been actively investigating who was behind the DOS attacks on Paypal, Amazon and other commercial sites. On December 16th they seized one the crucial servers used in the attack.

“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.”

To date the FBI has arrested four perps in connection with the DOS attacks. The sweet part of this deal is that if they are ultimately charged and taken to trial, Julian Assange could well be charged as an accessory for encouraging the attacks.