TOPSHOT – Messages written in chalk are seen on a pavement in Christchurch on March 18, 2019, after 50 worshippers were killed last week in two mosque attacks. – New Zealand Prime Minister Jacinda Ardern said she would be looking for answers from Facebook and other social media firms about how an attack that killed 50 mosque-goers was livestreamed on their platforms. (Photo by DAVID MOIR / AFP)