Do we really want an organization which is responsible for the deaths of 262 million people in the 20th century (that comes out to 5 human beings killed every minute for 100 years) to be the sole possessor of firearms? The professor who maintains the above website has defined the term democide to mean death at the hands of the government. A vast ocean of humanity has died at the hands of the state throughout history. Given that fact, think carefully about the following question:
Does an organization become legitimate by virtue of there being only one of its kind in existence in a given territory?
Is it the fact that the city police are the only police in the city limits (not strictly true, but close to true) that makes them legitimate? Does having a multiplicity of gun owners make gun ownership illegitimate for all but the one, legitimate organization, i.e. the police, the state? What is it about there being only one organization in a given territory permitted to use firearms (the state) that makes it legitimate? What is it that makes a multiplicity of gun owners illegitimate?
Does an individual who is being assaulted and fears for his life have the right* to use force, even deadly force, to defend himself? Let's say guns are banned by the state and an individual is assaulted by a gun-toting criminal - by sheer luck, the victim managed to wrest the firearm from the perpetrator without being harmed but the perpetrator is persisting in the assault. Does the now gun-bearing victim have a right to use that firearm to defend himself from the criminal? If not, then why does he have the right to use deadly force, so long as it is not with a gun? If so, then why is it illegitimate for him to bear a firearm at all other times so long as he only uses it when and where it is justified (as in the above case)?
I don't think it is at all obvious that the state has a moral imperative to be the sole purveyor of firearms and the use of force. When guns are outlawed, only the government will have guns. A rampaging gunman can kill as many as 30-something people (cf Virginia Tech) if there is no one to shoot back. Gangs can kill dozens or hundreds of people if there is no one to shoot back. Warlords and armed tribes can kill many thousands when there is no one to shoot back. But only the modern, taxing/inflating government has the resources to kill millions, hundreds of millions, when there is no one to shoot back.
In my view, a disarmed public at the mercy of an armed state is the most dangerous idea ever. Its historical track record is sheer carnage. It's a miracle that anybody believes in it, today.