Internet vigilante group Anonymous denied involvement on Thursday in the theft of personal information from over 100 million Sony PlayStation and Online Entertainment network accounts.
"We are trying to fight criminal activities by corporations and governments, not steal credit cards," Anonymous said in a statement published on a Facebook page used by the loose-knit "hacktivist" group.
"Anonymous has never been known to have engaged in credit card theft," the statement said. "If a legitimate and honest investigation into the credit card theft is conducted, Anonymous will not be found liable."
Sony, in a letter to a US congressional committee released Wednesday, said hackers had planted a file named "Anonymous" on the servers of the Sony Online Entertainment network at around the time members of the group carried out denial of service (DDoS) attacks on Sony servers.
The Japanese electronics company stopped short of directly accusing Anonymous of carrying out the data theft but said it bore some responsibility.
In a typical DDoS attack, a large number of computers are commanded to simultaneously visit a website, overwhelming its servers, slowing service or knocking it offline completely.
Anonymous, which carried out similar attacks last year against US companies which withdrew services to WikiLeaks, had vowed retribution against Sony for taking legal action against hackers who cracked PlayStation 3 (PS3) defenses to change console operating software.
Sony, in the letter to the House Subcommittee on Commerce, Manufacturing and Trade, noted that the large-scale data theft came shortly after the PlayStation Network suffered the DDoS attacks from Anonymous.
"Whether those who participated in the denial of service attacks were conspirators or whether they were simply duped into providing cover for a very clever thief, we may never know," Sony said.
"In any case, those who participated in the denial of service attacks should understand that -- whether they knew it or not -- they were aiding in a well-planned, well-executed, large-scale theft that left not only Sony a victim, but also Sony's many customers around the world," it said.
Personal information such as the user names, passwords, addresses and birth dates of more than 100 million accounts may have been compromised by hackers and the intruders may also have made off with credit and debit card data.
Anonymous, in its statement, said "while we are a distributed and decentralized group, our 'leadership' does not condone credit card theft.
"We are concerned with erosion of privacy and fair use, the spread of corporate feudalism, the abuse of power and the justifications of executives and leaders who believe themselves immune personally and financially for the actions they undertake in the name of corporations and public office," it said.
The PlayStation Network, which has been temporarily shut down by Sony, connects PS3 consoles to online games, films and more.
Players are still able to take part in games offline on consoles, but have lost the ability to challenge others on the Internet.
The PlayStation Network was launched in November 2006 and boasts about 77 million registered users worldwide.
Explore further: Hackers swiped PlayStation Network user data: Sony (Update 2)