When I was seven years old, I wanted to study tornadoes. I had seen the movie Twister and was fascinated by the speed, force and unpredictability of storms. To understand tornadoes fully, and create warning systems, you needed to get to the centre of a storm. Instead of chasing storms I have ended up chasing extremists for a living. In many ways these aren’t too dissimilar. Like storms, extremist movements are fast, have strong destructive potential and can change direction at any time. In my day job at the London-based Institute for Strategic Dialogue (ISD), I monitor extremist movements across the UK, Europe and America. My team works with cutting-edge technology partners and universities such as MIT to track and analyse harmful online content —