Again not caving but related by way of airport security. Back in the 1970s I went on a fishing trip to Ireland. In order to get around luggage restrictions we carried reels, lead weights, underpants and in my case, a Concertina in our hand luggage. I was stopped, outbound, and had my bag searched - everything out, pants, Concertina, everything. When we arrived in Ireland there was a call of "have you any maggots" (livestock of course) and when we answered "no" we were waved through with a smile. A member of a the party on the same trip a year earlier had tried to be "funny" and the result was a strip search, on the English side.
Years - decades - later I was leaving Sardinia with my son-in-law. We were both stopped at the same time, in adjacent aisles and had to demonstrate our playing of traditional music - Sardinian and English - on our respective instruments, carried as hand luggage, in order to prove that we had nothing secreted in them.