First of all, Clackers are still around, but not as kids of the 1960s and 1970s remember them. Their original design was basic (two acrylic balls attached to each end of a string, designed to be smacked together with satisfying force) but unfortunately dangerous.
Too much force, and the toy could explode, leading in one instance to the remarkably titled 1976 case, “United States v. An Article of Hazardous Substance Consisting of 50,000 Cardboard Boxes More or Less, Each Containing One Pair of Clacker Balls,” which led to the ban of acrylic Clackers.
