Last Friday, a lone gunman burst in on two mosques in Christchurch new Zealand, killing 50 people and injuring 50 more.
The gunman is a self-described eco-fascist who says he was inspired by other white nationalist extremists, as well as a hatred of muslims.
We look at how intelligence agencies view these threats, how the shooting may change that view, and how the online community is connecting these individuals.
Dave is joined by Washington Post security and intelligence reporter Shane Harris.
