As one of the younger members of the forum (20 y.o.) I have not had a problem as long as it stayed in my kilt hose. That's the key. Don't even take it out to show people what it is.

People frequently ask me "Is that a knife in your sock?" and I reply, "It's a sgian dubh". And they just say "Oh..." and forget about it.

I don't unsheath the sgian dubh, and it has never caused me problems.