JACINDA ARDERN, THE former Prime Minister of New Zealand, has told a Dublin conference that more needs to be done to combat extremist content online. One of the most significant events that occurred during her premiership was a terrorist attack in 2019 in which a white supremacist gunman killed 51 people at two mosques in Christchurch. The gunman livestreamed the first 17 minutes of the attack on Facebook, before the broadcast was taken down. In the weeks after the tragedy, Ardern’s government brought in stricter gun controls and proposed tighter regulations for social media content. Two months after the attack,...