Mobile phones were originally used by the military for battlefield communication. Used by you to play games.
TV, which is used to watch video information, is connected to a game console to play games.
network, originally for information exchange among military units. Used by you to download and play games.
potassium bromide was invented to prevent masturbation. You call it a tranquilizer.
graham crackers, invented to suppress sexual demand. Used by you to eat,
microwave, invented in World War II to track Nazi fighters. Used by you to help you eat.
Champagne, in order to prevent the bubble from forming in the brewing process, is used by you to spray bubbles specially (I can't imagine the inventor, seeing your expression of shaking champagne)
LSD hallucinogen, which relieves the pain during childbirth through drugs, has been sucked by you and now becomes a drug.
Radio astronomy was initially responsible for searching and identifying telephone interference signals. Now he has become an astronomer (that group of engineers also became the first generation of radio astronomers)
Hybrid rice was originally used to feed pigs, and now you have eaten both pigs and hybrid rice.
gunpowder. At first, Taoist priests couldn't practice the elixir to eat it, but they were cleverly slapped.
compass for navigation. Used by you to see feng shui.
genetically modified food. It's really for you. You said it was poisonous.