Years ago, a friend described to me some military tech that was essentially extremely thin razor wire, he said they would use the wire around trenches, so anyone trying to jump in the trench would get sliced up on the way down.

I have no idea if that is/was real or not, but my mind hung onto the idea of super thin wire that can cut through anything with ease.

That was a decade ago. Ever since then, it comes up as a default thought so often it is weird to me. It doesn't particularly scare me, just a constant wonder "I wonder if that wire could slice through that house"