Obama criticises Sony film decision
Barack Obama has criticised Sony Pictures' decision to cancel the release of a movie about a plot to assassinate North Korean leader Kim Jong Un, saying the studio "made a mistake".
The president's intervention came shortly after the FBI said a hack on Sony that saw thousands of internal files leaked online was carried out by the North Korean government.
Foreign Secretary Philip Hammond said he was "deeply concerned" at the US agency's findings and urged Pyongyang to "work constructively with the outside world instead of attacking it".
Since the attack on Sony's internal network, which was carried out by a group calling themselves The Guardians of Peace, thousands of emails, personal details and even films from Sony have been leaked online.
On Wednesday, controversial film The Interview had its release cancelled after terrorist threats were made against cinemas that choose to show it.
At his end-of-year press conference Mr Obama said of Sony's decision: " I wish they had spoken to me first."
He added: "We cannot have a society in which some dictatorship someplace can start imposing censorship..."
Envisioning other potential flashpoints, he suggested situations in which dictators "start seeing a documentary that they don't like or news reports that they don't like".
"We will respond" to the attack, he added, although he offered no details.
The FBI had earlier said it believed the North Korean government was behind the cyber attack.
The agency said: " As a result of our investigation, and in close collaboration with other US government departments and agencies, the FBI now has enough information to conclude that the North Korean government is responsible for these actions."
Its statement continued: " We are deeply concerned about the destructive nature of this attack on a private sector entity and the ordinary citizens who worked there.
"Further, North Korea's attack on Sony Pictures Entertainment (SPE) reaffirms that cyber threats pose one of the gravest national security dangers to the United States. Though the FBI has seen a wide variety and increasing number of cyber intrusions, the destructive nature of this attack, coupled with its coercive nature, sets it apart."
As well as the cancellation of The Interview, a film which North Korea called an "act of war", the cyber attack has seen emails between Sony executives criticising Angelina Jolie and the personal details and social security numbers of thousands of staff appear online.
The Guardians of Peace have since praised Sony's decision to cancel The Interview's release, and told CNN that no more Sony data would be released if the firm continued to comply.
The FBI confirmed that analysis of the malicious software used to attack Sony linked the breach to North Korea.
It said: "Technical analysis of the data deletion malware used in this attack revealed links to other malware that the FBI knows North Korean actors previously developed. For example, there were similarities in specific lines of code, encryptions algorithms, data deletion methods, and compromised networks."
North Korea has previously denied involvement in the hack, although when one state spokesman was questioned by the BBC he replied "wait and see".
"North Korea's actions were intended to inflict significant harm on a US business and suppress the right of American citizens to express themselves," said the FBI.
"Such acts of intimidation fall outside the bounds of acceptable state behaviour. The FBI takes seriously any attempt - whether through cyber-enabled means, threats of violence, or otherwise - to undermine the economic and social prosperity of our citizens."
The statement concluded: "The FBI will identify, pursue, and impose costs and consequences on individuals, groups, or nation states who use cyber means to threaten the United States or US interests."
Mr Hammond said: "I unequivocally condemn these cyber attacks and am deeply concerned at the findings of the US investigation, which seems to provide further evidence of North Korea's blatant disregard for international norms and obligations.
"I urge North Korea to work constructively with the outside world instead of attacking it."