A very old joke has just popped up from my memory.
This guy sees a new machine outside the post office, and noticed a couple of blokes walk up to it, insert a coin, put their nether regions against it, then walk away with a smile.
Great idea he thinks. Puts coins in the slot, todger up to the machine. He is assailed with an agonising pain, and looks down to see a blue button sewn neatly on the end...
Andy