Terrorism and online extremism

The rapid expansion of cyberspace has greatly facilitated the strategic shift of traditional crimes to online platforms. This has included malicious actors, such as extremist organisations, making use of online networks to disseminate propaganda and incite violence through radicalising individuals. Here, we provide some insight into the phenomenon of online extremism and the current research landscape within this field. Firstly, we discuss how it is defined within academia and practice, and key examples of extremist activity in online environments. We then discuss research findings across both computational and social science disciplines, where we further consider the ways in which extremists use the Internet, counter-extremism initiatives, as well as some of the computational approaches that are commonly used within this field. Finally, we provide a brief outlook on future perspectives in online extremism to further current practices and research.