As pro-gun activists always point out, if you ban guns, you do not stop mass killings. You only stop mass gun killings. In countries where guns are banned, you still have bombs going off and mass killings using knives. You could also kill quite a bit of people with a car, and nobody wants to ban those things, but we're starting to enter a new world. Autonomous vehicles may eventually make driving illegal. It'll just be too dangerous when compared to driverless technology. Computers could easily track people who buy all of the raw chemicals to build bombs, and regulations could vastly restrict who could own a gun or knife. What stops us from doing this? Well the 2nd amendment and the idea that everyone should be able to own a gun. That along with the attitude of the people. However, the world is changing, and here we are with the means to change a lot. What if we lived in a world where terrorism and mass killings were impossible? Would we want to live there?