If you can afford a gun, you can afford to secure it when it's not in your possession. If you don't want to secure it, then you can afford to lose it. You'll get no sympathy from me. No one ever has. I know three different people, a cop, a pastor, and a business man who have had guns stolen (house, car, and business) as well as a a disturbingly large number of reports on this site of people losing guns by way of theft. I have no sympathy for any of them. Tough luck.
So my $40,000 dollar Yukon with door LOCKS does not constitute "secure' in your little 3 page book? Would it also be my fault for not "securing" my vehicle if some punks broke the window and stole it, then hit someone in a crosswalk and killed them?
Where does my liability and responsibility end in your nirvana?

