"A gunman who killed 49 people at two New Zealand mosques live-streamed the attacks on Facebook for 17 minutes using an app designed for extreme sports enthusiasts, with copies still being shared on social media hours later. The live footage of Friday's attacks, New Zealand's worst-ever mass shooting, was first posted to Facebook and has since been shared on Twitter, Alphabet Inc's YouTube and Facebook-owned Whatsapp and Instagram. The shootings in New Zealand show how the services they offer can be exploited by extremist groups, said Lucinda Creighton, senior advisor to the Counter Extremism Project. She said the attacks were shown live on Facebook for 17 minutes before being stopped. 'Extremists will always look for ways to utilise communications tools to spread hateful ideologies and violence,' she said. 'Platforms can't prevent that, but much more can be done by platforms to prevent such content from gaining a foothold and spreading.'"