Maybe, but is that all they want? It seems that something important is left out of the story. In the classical model of terrorism, instilling fear (along with causing death and injury) is not an end in itself. It's a means to an end.

Terrorists don't necessarily get a kick out creating carnage and fear (though it is possible). Primarily they want the survivors' fear converted into action aimed at changing their government's policy. Thus terrorism, if it to have any meaning, is a political, not a sadistic, act. In the paradigmic case a weak nonstate group, unable to resist a state's military or to change its policy directly, terrorizes the civilian population of that state in the hope it will demand a change in foreign or domestic policy. (Let's leave aside for this discussion that terrorism has been strategically (re)defined by the United States and its allies such that it can apply only to their adversaries, even when they attack military targets instead of civilians.)