Is that they know so many things that just aren't true.
Case in point. A commenter named George W. at this anti-gun post says the following,
"There are lots of countries with sensible (“Crazy? Police record? No gun for you”) gun regulations. People there still own guns, and they are also present in organized crime. But individual violent jerks or crazies have a harder time getting them, and the result is a much lower murder rate. "
So, those countries with "sensible gun regulations" have a much lower murder rate. Lower than what? I'll assume he means lower than the U.S. There's only one problem with his statement. It is, like virtually all arguments in favor of gun control, patently false.
Let's look at the per capita murder rates of countries with "sensible gun regulation." For the purposes of this experiment I'll define "sensible gun regulation" as regulation that is far more strict than what we see in the U.S. Virtually all of the countries on the list have strict gun bans for anyone other than police or military
Here's a list of Murders per capita of 62 nations. The U.S. comes in at #24. I see many gun control paradises on that list which have murder rates above that of the U.S. These are places that would drive Sarah Brady & Paul Helmke crazy with daily orgasmic ecstasy, yet people are being killed at a rate far above that of "gun-crazy" America. Columbia, S. Africa, Jamaica, Mexico, Venezuela, and Zimbabwe are a few of the countries on the list. Jamaica comes in at #3 in the world yet they banned handguns completely in 1974 and they're an island, yet the bloodshed continues. Here's a graph of their murder rate. In 2009 Jamaica had its highest murder rate ever.
So, the U.S. does NOT have a higher murder rate than countries with sensible gun laws. Confirming my statement took only a few seconds typing in "murders per capita country" into Google.
This is why I have trouble respecting the opinions of people who make these kinds of claims. The facts are out there. They can be found in a matter of seconds, yet people interested in restricting my rights keep on spewing their crap.
That said, George appears to be part of the "blame Palin for the AZ shooting" ilk, so I think it's safe to say that providing evidence to back up his claims is not his strongsuit.
H/T to Robb Allen