Individuals in possession of a gun at the time of an assault are 4.46 times more likely to be shot in the assault than persons not in possession (Branas et al, 2009). It would appear that, rather than being used for defense, most of these weapons inflict injuries on the owners and their families."This type of lie makes me laugh too, because it is common and because many people fall for it. The leap of logic that people are invited to make is that a "rate of increase" is equivalent to greater numbers.
Aside from the statistical error, the action bias the writer is attempting to instill is to not defend yourself or present any resistance, because doing so is risky. By all means, if you have no intention to defend yourself, I concur with the conclusion, don't carry means to defend yourself.