Removing offensive social media posts ineffective - researcher

An investigator into social media and terrorism says taking down offensive content on social media is an endless whack-a-mole that isn't very effective. Calls for social media to be regulated have escalated after the failure of platforms like Facebook and Youtube to take down the content during the Christchurch terror attacks. Benjamin Decker from Harvard Kennedy School in Boston investigates the online radicalisation of mass shooters and jihadists. He speaks to Susie Ferguson.