Social-media platforms are destroying evidence of war crimes

TECHNOLOGY HAS always mattered in the prosecution of war crimes. The Nazis who stood trial at Nuremberg were damned not only by war reporters’ photographs and films but also by their own typewriters and mimeographs. Forensic science and satellite imagery aided the prosecution of Rwandan and Yugoslavian war criminals. In August Salim Jamil Ayyash was convicted in absentia by the Special Tribunal for Lebanon for his role in a bombing in 2005 that killed 22 people in Beirut, among them Rafik Hariri, the country’s former prime minister. Mr Ayyash was first identified by algorithmic analysis of mobile-phone metadata.