The first time I ever read that term (it's an Anglo-American common law phrase meaning unorthodox, usually gay, sex) I had no idea what it meant, because I was probably six or seven years old.
But there it was, in the "Police News" section of a cruddy small-town newspaper, that Mr. X and Mr. Y had been arrested for crimes against nature, in the men's room at a highway rest stop. What could they have done? Defied gravity? Fused atoms at room temperature? Reversed the flow of time?
In fact, until today, I'd never read about any crime where the term actually seemed to fit. Until today, that is.