What ISIS can teach us about fighting far-right violence online

Prime Minister Justin Trudeau is in Paris today, set to join world leaders at a summit called "The Christchurch Call." It's designed to help politicians and big tech work together to eradicate hate and extreme speech online.

The event comes two months after a white supremacist killed 51 people at two mosques in Christchurch, New Zealand.

By no means is online extremism a new phenomenon, as earlier this decade big tech was confronted...