The thing that gets me about some of these stories is that nobody bothers to explore the theory that someone may have planted the gun in the luggage.
In other words, an angry girlfriend/boyfriend or spouse knows the traveler has a gun and knows where it is before they leave for the trip.
At the last minute, the angry partner puts the gun in the luggage without the traveler knowing about it. And voilà, the traveler is caught, charged and convicted of a felony.
I'm not saying this happens in every instance but when this happens to someone who has never had any problems in the past and isn't usually negligent, the theory should be considered. I've had enough girlfriends and ex-wives mad enough at me to try this.
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein