LOS ANGELES - Sony Pictures Entertainment (SPE) 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 United States officials have blamed on North Korea, and took place on the same day that the pariah state experienced a complete Internet outage for hours before links were restored yesterday.
However, several US officials close to the Sony investigation said the US government had not taken any cyber action against Pyongyang.
On Friday, US President Barack Obama had vowed to respond to the Sony cyber attack "in a place and time and manner that we choose".
US-based Dyn, a company that monitors Internet infrastructure, said the reason for the outage was not known, but could range from technological glitches to a hacking attack.
Matthew Prince, chief executive of US-based CloudFlare, which protects websites from Web-based attacks, said the fact that North Korea's Internet was back up within hours "is pretty good evidence that the outage wasn't caused by a state-sponsored attack, otherwise it'd likely still be down for the count".
Almost all of North Korea's Internet links and traffic pass through China, but the latter dismissed any suggestion that it was involved as "irresponsible".
A group calling itself Guardians of Peace took credit for infiltrating Sony's computer systems in retribution for plans to release The Interview, a film which mocked North Korean leader Kim Jong Un.
The hackers destroyed numerous Sony computer files and published several embarrassing e-mail messages containing unflattering remarks about movie stars and confidential celebrity pay information as well as employees' personal details.
Some of that material has now been posted on Twitter, said an attorney for SPE, David Boies, in a Monday letter to the company's lawyer, demanding that it be removed.
"Someone using the Twitter account @bikinirobotarmy is in possession of, and is using this Twitter account to publish SPE's stolen documents and information," Mr Boies said in a copy of the letter posted on website Scribd.com.
In the letter addressed to Twitter's general counsel, Vijaya Gadde, Mr Boies asked that the Twitter account be suspended.
If the company fails to comply, he 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".