There has to be something more constructive that we can say about all this besides, "This guy's a moron." So, here goes:
The problem with this guy's basic assumptions is that SOMEHOW, prior to the invention of the firearm, people managed to kill each other. In fact, back before the invention of the firearm, the world was a pretty brutal place. Now that the firearm has been invented and widely dispursed, you go to places like Liberia and Sierra Leone, and you see that without ready availability of guns, the world is STILL a pretty brutal place. In other words, no matter where you go, no matter how many guns there are, there are ALWAYS going to be people who want to kill other people.
Now! Are guns on the streets a threat to the police? You betcha! Are guns a threat to local safety? Oh yeah! Does the availability of a gun grant anyone the ability to wreak havoc on their community? Sure it does! And, that's EXACTLY why the 2nd Amendment is so critical. The right to bear arms grants us the ability to take action against WHATEVER people are trying to kill other people, be it some lawless group, or be it some renegade protected by the guise of official authority who attempts to use the power of his corrupt office to abuse the people. (The threat to liberty anywhere is a threat to liberty everywhere.)
So, in response, I say, yes. The world is a dangerous place. And I, for one, would rather be armed than to trust everyone in the whole world to remain disarmed. (See North Korea.)