Throughout history, mankind has never stopped trying to create various types of weapons for various purposes. At the same time, while mankind created them, certain prohibitions on its use came out. For example, the popes banned the crossbow, and Homer spoke disapprovingly of the bow. In the 21st century, the scale of invented weapons reached a completely different level of danger, which can be called deadly. Which of the existing military guns managed to be banned and why are these inventions so dangerous?