In the wake of the Easter Sunday suicide attacks by Muslim youth inspired or instigated by the Islamic State (ISIS), there is renewed interest in understanding how youth radicalisation happens. Some are asking whether, among other factors, the internet and social media also contribute to it. Since 21 April, news media have revealed how the extremist preacher Zahran Hashim, leader of now-banned National Thowheed Jamaath (NTJ), had used Facebook to publicly call for “the death of non-Muslims”, while he worked in private online chatrooms to persuade young men and women to sacrifice themselves. Hashim had uploaded some of his vitriolic sermons to YouTube as well. Following the 4/21 attacks, the Google-owned video sharing platform quickly removed them …