Terrorism has gone viral. The Christchurch massacre at two New Zealand mosques that left more than 50 people dead was livestreamed on Facebook. In 2015, two reporters in Virginia were shot while broadcasting live and the shooter uploaded videos to social media channels that are still available today. And in 2014, the beheading of James Foley by Isis (Islamic State) forces in Syria spread across the internet within minutes of being uploaded. The world can't figure out what to do about staunching the flow of this content online.

Now the leaders of France and New Zealand have a proposal.