This paper investigates whether the counter-terrorism measures developed and implemented within the European Union have a universal character and are equally effective in the context of various types of terrorism. The authors focus on the strategies applicable to the terrorist activities online, since information and communication technology is perceived as the fastest growing and continually changing field of the terrorist threat. So far, most of the counteractions and security strategies have been subordinated to the jihadism combating. However, in recent years, the significant growth of threats coming from far-right and far-left terrorist activities has been observed. It raises questions about the capability of instruments to prevent and combat other types of terrorism as well as jihadism. The research was conducted in particular, on the basis of international organizations’ reports, the authors’ observations, and practitioners’ remarks. As follows from its results, there are significant differences in the phenomenon, current trends, and modus operandi of the perpetrators in the jihadi, far-right, and far-left terrorism. Consequently, it is possible to conclude that the effectiveness of chosen countermeasures, subordinated – as a rule – to the fighting of the jihadi extremists, is doubtful in preventing and combating far-right and far-left terrorism.
