The impunity of some of the world’s most frightening men is under threat from people stereotyped as geeks in basements around the world. In the 21st century, well-informed and observant social media addicts have extraordinary powers. Eliot Higgins started watching and reporting on war from the comfort of his living room in 2012. Five years later, he’s using his skills to help the International Criminal Court in The Hague to prosecute war criminals. It’s been a strange journey.