This year will go down in history. For the first time a civilized nation has full gun registration! Our streets will be safer, our police more efficient, and the world will follow our lead into the future!It gets cited a lot - and yet Hitler never said it. In fact, it's nonsensical, because guns were entirely outlawed in Germany after WWI as part of the war settlement, then registration was phased in by the Weimar Republic in 1928. Instead of Hitler taking guns away from his domestic population to control them, as gun nuts claim, in 1938 he did away with gun registration for people who weren't suspect: i.e. Jews, Gypsies, etc. couldn't buy guns, but Germans? No restriction except for age - and he lowered the age. [background]
Essentially, Nazi Germany is a counterproof to claims that gun control was used by fascists to control the domestic population. But this quote is still very often used against gun control. (Here's an example. Here's another.) It might be instructive to watch phrases like this to track them in the discourse.
What's astounding is the nonchalance people evince when checked on it - after all, it doesn't matter if he actually said it (sometimes people say exactly this!) because it's just something he would have said.