A lot of Harry's points get to me, because there's a lot of chestbeating that goes on here, and exaggerating the pro-gun side of things while ignoring other factors.
John Lott isn't the only researcher out there, you know. His data doesn't exactly show the clear cut "guns = good, no guns = bad" relationship a lot of you seem to want to see. At the same time, I am quite pleased to say that it doesn't show a bad relationship between guns and crime. I just wish you guys would quit being like "zomg stfu noobz, Lott sez so!"
As for the non-scientific measures ("Look at how much worse it's gotten since then! Banning guns isn't helping!"): you're making it too easy for them to say either "imagine how worse it would be if criminals could buy all the guns they wanted" or "that's because the gun lobby has kept us from making the bans that really count."
4 specifically: You'll note that DC has a population density of about 9300/square mile while Indianapolis is more like 2200/square mile. Likewise, DC has Virginia for criminals to buy guns in. Banning guns doesn't work as well in an open system.
7 specifically: Too easy for them to say "well that's obviously not our intention" ("that" being what happened in Nazi Germany, Cambodia, etc...) and leave it at that, then attack you for implying that America would ever do that if you push the point.
12 specifically: Actually, it's more like two-thirds as many, not two to three times as many (though I would also point out that private citizens are not handed a gun and instructed to go confront armed criminals). That 2-2.5 million defensive gun usage statistic is likely quite high, though even the DOJ (I believe) puts the figure at hundreds of uses a day when a serious crime has already been initiated.
5 and 6 specifically: Much better luck bringing these points up. It's a good one, and people should be more aware that the law expects them to take responsibility for their safety.
Several of the "what makes them so important?" ones: Some people are more likely targets, and therefore would warrant more protection. Of course you can use 5 and 6 to make the point that since everyone is a potential target and expected to be responsible for themselves, they should have the tools they need to protect themselves.
So yes, if you could please stop the mindless repeating of statistics. You have too many points on your side to make it worth undermining your credibility by mentioning dubious statistics (though I would be perfectly content to cite Lott, I would only use him to say that guns had either a net negligible or slight positive effect). Also, after reading about the defensive gun usage survey's methodology I just shake my head every time I hear the 2-2.5M annual DGU statistic. And then, just think about it: that would mean that a very large percentage of people had to pull their guns each year (if nationwide there proportionally as many people who carried regularly as there are people in Texas with CHLs, and only 20% of DGUs occurred away from the home, you as a CCWer would be pulling, on average, once every eight years with that statistic).