Several websites operated by Sony have been attacked by hacktivist group Anonymous, allegedly for the corporation's support of the US Stop Online Piracy Act (SOPA).
The Sony Pictures website and its Facebook page were both hacked and defaced by the attack, although both were quickly recovered and repaired by the company.
The attack follows a video posted on YouTube last month by Anonymous members warning Sony that an attack was imminent.
Claiming responsibility for the attack, alleged Anonymous member s3rver_exe said via his Twitter feed that he had been able to access admin usernames and passwords in the attack.
"The hack wasn't big but still the servers were vulnerable and I got access to the admin too. #OpSony."
The SOPA bill is designed to extend the ability of US law enforcement and copyright holders to fight the online exchange of copyrighted material.
The bill has angered many large technology companies including Google, Facebook and Twitter, who argue that it may leave them open to prosecutions or court orders over which they have little control.
Last month security firm Kaspersky decided to quit the Business Software Alliance over the BSA's support of the bill.
Following a string of cyber attacks against Sony last year in which over 100 million customer details were accessed, the company appointed its first chief information security officer, Philip Reitinger, in September 2011.
Previously, the company admitted that it expected the hacks to cost it in the region of £105m.
Sony declined to comment on the story today.
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