article: Media playback is unsupported on your device 12 January 2015 Last updated at 22:04 GMT The accounts were hacked by a group claiming to support Islamic State, while President Obama was giving a speech on cybersecurity. Mr Earnest said that officials were monitoring the hack, but cautioned "there is a pretty significant difference between what is a large data breach and the hacking of a Twitter account". The accounts, which usually provide updates on strikes against IS, have now been suspended.
summary: White House Press Secretary Josh Earnest has played down the significance of a hack involving the Twitter and YouTube accounts of US military command.