Speaking of the Miranda Rights, I heard somewhere, years back, that the cop only has to make sure that the suspect knows his rights, not necessarily to read him those rights (mind you, they routinely read them said rights as a standard CYA measure). That said, unless a court of law will readily rely on pop cultural osmosis (that is, everybody everywhere knowing that Darth Vader is Luke’s father, hope I didn’t spoil that for you) in determining the legality of a confession, I would only see this coming up for suspects who happen to be cops, lawyers, etc.
I was just using that as an example. However, what I really want to know is, is it kept secret entirely?