Klackers, or Clackers, sometimes referred to by other brand names such as Ker-Knockers, are one of the most infamous kids toys from the 1970s. Klackers comprised two acrylic balls, often brightly coloured, on a string with a small handle in the middle. When you swung the balls up and down, they would bang against each other, making a "clacking" sound. Clackers were very similar in appearance to the Argentinian weapons called bolas. Yet no-one thought that these things could be lethal.
They were a playground craze that swept across Britain and America in the early 70s. Kids with skill, could make the Klackers balls meet at both the top and bottom of a circle. Everyone seemed to have a pair, yet parents and teachers became concerned about the safety aspects of kids smashing two hard plastic balls together at high speed. Playing with the balls could cause bruised hands and arms, and the balls would sometimes shatter into tiny sharp projectile shards. Lacerating young innocent faces. Soon schools started to ban them from the playground.
In the United States, they were classed as a "mechanical hazard" in a 1976 count case, regarding the US government's attempt to seize a shipment of "Clackers" under the Federal Hazardous Substances Act. Amusingly the court case was called (I really do love this title)... United States v. Article Consisting of 50,000 Cardboard Boxes More or Less, Each Containing One Pair of Clacker Balls.
Klackers has a brief resurgence in popularity in the 1990s, but soon disappeared back into the history of crazily dangerous toys of the past.