In England, as in the rest of the world, parents fight with their children about homework. The children don't want to do it, but the parents insist that future freedom is at stake. (Since chronic failure is no way to go through life, son.)
However, an English inventor decided the best way to emphasize the loss of future freedom was to take away existing freedom until the homework is done. British slacking children now can suffer being literally attached to a 21 pound ball until either their homework is done or 4 hours have elapsed. The heavy ball makes normal procrastination tasks like walking to the refrigerator and getting a snack, or walking to the phone to call your friends, much much more difficult.
This idea is not new, by any means. I've heard of American parents who tie their homework-refusing offspring to a chair as a way of insisting on homework time. And the ball at least has a time limit and safety key.
Also, the ball is apparently a joke invention. A chindogu, essentially. The tying to a chair, that was serious. Yikes.