Sociologist Ruud Koopmans conducted a research on Muslims and concluded that 44% of the Muslims can be labelled as fundamentalist. Although most of them have a peaceful mindset, their ideas could be a breeding ground for terror, such as the Charlie Hebdo attacks. A lot of readers reacted with enthusiasm to the article about Koopmans research. They felt ‘supported’ in their already existing ideas. There is however also some critique on the article and the research. Some of them referred to a different view on the same research, where Koopman argues that Islam nót the problem. Researcher Martijn de Koning criticized the research in itself, arguing that Koopman uses a certain (wide) definition of ‘fundamentalism’.