US officials have blamed the hacking of Sony Pictures on North Korea

Sony Pictures has threatened Twitter with legal action unless it removes confidential material stolen from the movie company's computers that someone has posted on the social networking site.

The threat is the latest fallout from the hacking of the movie studio, which US officials have blamed on North Korea.

A group calling itself "Guardians of Peace" took credit for infiltrating Sony's computer systems in retribution for plans to release the film "The Interview", which mocked North Korean leader Kim Jong-Un.

The hackers destroyed numerous Sony computer files and published several embarrassing emails containing unflattering remarks about movie stars and confidential celebrity pay information.

Some of that material now has been posted on Twitter, said an attorney for Sony Pictures Entertainment (SPE), David Boies, in a December 22 letter to the company's lawyer, demanding that it be removed.

"Someone using the Twitter account name: @bikinirobotarmy is in possession of, and is using this Twitter account to publish SPE's stolen documents and information," Boies said in a copy of the letter posted on the Scribd.com website.

In the letter addressed to Twitter's general counsel Vijaya Gadde, Boies asked that the Twitter account be suspended.

If the company fails to comply, Boies wrote, "SPE will have no choice but to hold Twitter responsible for any damage or loss arising from such use or dissemination by Twitter, including any damages or loss to SPE or others, and including, but not limited to, any loss of value of intellectual property and trade secrets resulting from Twitter's actions."

Meanwhile, in a separate development, some 250 independent movie theater owners expressed "solidarity" with Sony Pictures on the change.org website.

The art house cinema owners "reaffirm clearly our dedication to the value of freedom and the absolute necessity to keep our film industry free of restriction, censorship and violent intimidation," they wrote, encouraging independent movie houses to dare to show the film.

Just last week, Hollywood star George Clooney slammed the industry for failing to stand up against the cyber threats that ultimately led Sony Pictures to cancel The Interview's planned Christmas Day release.

No one, the actor said, was brave enough to sign the petition, fearing that doing so could make them vulnerable to a hacking attack like the one that befell Sony.