Nintendo's Wii video game system features games with simulation of tennis and boxing. To play the game, the players use motion-sensitive controller in their hand. When playing the game, some players, in making the motions necessary or the sport, have lost of their controllers. The controllers have crashed into other objects, including television sets, and injured the players. Players who have been injured brought a class action suit against Nintendo for a defective wrist strap on the controllers, designed to keep the controllers from flying out of control.