Tension between the USA and North Korea is rising after a cyber-attack on the movie company Sony Pictures. Sony cancelled all screenings of its movie 'The Interview' after a group, calling itself The Guardians of Peace, threatened to attack cinemas that showed it. The group said the attacks would be "9/11 style". The movie is a political comedy about two US journalists wanting to interview and assassinate North Korean leader Kim Jong-un. The group also threatened Sony that it would put more confidential data online that could damage the company if it did not stop the movie.

Sony cancelled the movie "in the interests of public safety". President Obama said: "We cannot have a society in which some dictators some place can start imposing censorship here." He added: "Imagine what they start doing once they see a documentary that they don't like or news reports that they don't like." A US senator said the cyber-attack was "an act of war" and "the greatest blow to free speech". Another politician said: "America has lost its first cyber-war." An actor tweeted: "Everyone caved [in]. The hackers won. An utter and complete victory for them."