Sneaking a weapon onboard:

I thought it was amusing when my son tried to bring a machete knife onto a plane - it was a juggling knife, not a weapon - but of course the security people did not seem to agree with him.

I thought it was amusing (this happened many years ago on a domestic flight) when I saw a family waiting for twenty minutes to board, while security decided whether their fifteen foot long elephant tusk was a weapon. (They were allowed to carry it on the flight. It was slightly curved, pointed at one end, and wrapped in brown wrapping paper.)

But I was unamused and worried at Tel Aviv Airport when security said they had found a weapon, a pointed metal object, in one of our carry-on bags. Fortunately my wife quickly realized they were x-raying an antiquity we had purchased, a 3,000 year-old spear head. The security agent examined the delicate object and then let us take it on board.