I'm sorry, but under the US Constitution, the people who have something to justify are those who are arguing to infringe the right to keep and bear arms. Under the Constitution, as indicated by the Supreme Court in both Heller v. DC and McDonald v. Chicago, I have a clear right to self defense. I cannot be denied that right without due process of the law. However, if you want to look at data, look at the homicide rates in places like Chicago, DC, and New York, as compared to neighboring localities that don't have bans. When you cross the Potomac River from Virginia into DC, even though the demographics remain similar the crime rate skyrockets. That same crime rate remains similar when moving from DC into neighboring counties of Maryland (that also have restrictive firearms laws). You get similar effects near Chicago, New York, and other cities in the US that prohibit or severely restrict firearms ownership. Prohibition simply doesn't work, because it only really hinders the law abiding. If we banned guns today, only the law abiding citizens would turn them in. The criminals would just keep them, and we would have an even greater force disparity between the criminals and law abiding citizens. And you can't really compare Europe and the US because of some severely fundamental cultural differences. Europe has a long history of classism and statism, where people have a history of submitting to authority. The same is not true of the US. The US tended to get many of the people who were anti-authoritarian to settle there, and we are still as a nation closer to our frontier roots than the vast majority of Europe is. The problem is that you can make the same arguments about any other right. Everyone would be pleased if we could keep Nazis, or Klansmen from spewing hate-filled propaganda, or keep hardcore pornographers from peddling filth, or [insert other offensive speech here], but the only way to limit such things is to infringe everyone's rights. Bad things happen, and we can't stop them all. It's the price that we pay to have a free society, that even "bad people" get freedom until they do something to justify losing it.