Facebook left horrific Islamic State videos on its site for three years, the Daily Mail can reveal. Despite repeated criticism of the social media giant for failing to protect users, the infamous Cubs Of The Caliphate film posted in March 2015 was one of several that could still be viewed until last week. Thousands of users have watched the video, which shows a young boy – pictured – shooting dead a teenage hostage. A bomb tutorial used by Manchester Arena bomber Salman Abedi was repeatedly uploaded. Experts fear there is a deliberate attempt to use Facebook to target potential British jihadi recruits. Former UK counter-terrorism chief Sir Ivor Roberts said the failure to take down the videos was ‘chilling and inexcusable’. Sir Ivor, former head of counter-terrorism at the Foreign Office and now an adviser to the Counter Extremism Project, said: ‘Facebook’s recent series of apologies and assurances that they will take action to protect their users is clearly fake news.'