DO NOT accidentally carry your very favorite Spyder penknife in your pocket when on your way to a flight. It ends up in the garbage can. Happened to me last time.
The garbagemen must have fun finding goodies in those airport cans. That was a $55 pocket knife.
I remember also getting hassled at Canadian Customs a couple of years ago as they rummaged through my luggage. "Any knives?" they asked. "Well, my Swiss Army Knife is in there." This was a hunting trip. Big lecture about bringing knives into Canada, and they took it away from me. Good grief. But it was a rusty old one, and the essential beer bottle-top opener was rusted into the case.
It's a good thing they didn't find the sharpened grapefruit spoon I always travel with, in case I encounter a good grapefruit.