It used to be that a spree was mainly understood as a wild drinking carouse, with the emphasis on spontaneity and abandon. Then it was used metaphorically, as in a “shopping spree.”
American journalists began to write of “killing sprees” by murderers recklessly killing people at random (“spree” fits so nicely in headlines).
But they go too far when they refer to terrorist bombing sprees. Targeted, purposeful acts like these lack the element of spontaneity and disorder that characterize a spree. Do they mean perhaps a spate?