Someone pointed out a few months ago that someone posting a no-gun sign and not having some minimal screening, maybe metal detectors at the door, should be liable for gun crimes committed there. They know or should know that law-abiding people will obey the sign and criminals won't. The sign would at least make sense if accompanied by having to walk through a metal detector.

I'm grateful for the otherwise law-abiding people who bend the rules and don't obey the sign.