Whose bright idea was it to make a toy that was guaranteed to shatter on impact? The makers of Clackers, that's who.
This early '70's fad was thankfully short-lived, but not before more than a few kids were injured while playing with the toy, much to their parent's distress. Reports of flying glass, eye injuries and related problems were the beginning of the end for this popular toy.
Too bad. It was fun while it lasted.