Sony puts 'The Interview' on YouTube

Tickets for the film "The Interview" is seen held up by theater manager Donald Melancon for the media at Crest Theater in Los Angeles, California December 24, 2014. [Photo/Agencies]

Google said it had weighed the security implications of screening the movie - described by reviewers as "profane" and "raunchy" - after Sony contacted the company about making it available online.

"But after discussing all the issues, Sony and Google agreed that we could not sit on the sidelines and allow a handful of people to determine the limits of free speech in another country (however silly the content might be)," Google's chief legal officer, David Drummond, wrote in a blog post.

Google has an "enormous" infrastructure that is well tested in fighting off denial of service and other attacks, said Barrett Lyon, principal strategist with F5 Networks and an expert in Internet network security. "I wouldn't imagine seeing 'lights-out' at YouTube," he said, adding that Microsoft could be more vulnerable

Sony pulled the movie after major theater chains refused to show it. That followed threats of September 11, 2001 style attacks from Guardians of Peace, the group that claimed responsibility for the cyberattacks against Sony.

A national security official said on Tuesday that US authorities did not take the hackers' threats against theatergoers seriously.

The White House on Wednesday praised the decision to release the film after Obama's rare public rebuke of a corporation last Friday that took the studio aback.

Obama has vowed respond to the cyberattack "in a place and timing and manner that we choose."

Japan, meanwhile, has begun working to ensure basic infrastructure is safe and to formulate its diplomatic response, officials said, fearing it could be a soft target for possible DPRKn cyberattacks in the escalating row over the Sony Pictures hack.