on facebook, fewer than 200, we're told, watched the attack live. facebook says it removed it 29 minutes after it started. within 24 hours after that users attempted to re-upload it 1.5 million times. judge that for what you want. the interest and reach aside, new zealand's prime minister saw a need to regulate such online extremism and she asked the world to join her in a pledge. >> when it came to the way that this attack was specifically designed to be broadcast and to go viral, responses to that needed a global solution. there is more work to be done here when it comes to stopping the proliferation of online and violent extremism. that was the basis of the court. >> 18 governments signed onto the christchurch call for action.