Hide In Plain Sight

The phrase hide in plain sight is a part of our cultural vocabulary. You won't hear it in casual conversation very often, but it occurs frequently in written works.

I knew that there was a movie of the same name, and found a book with that title after a brief search. News stories and essays are a favorite playground for this phrase as well.

I haven't had much luck searching etymological dictionaries on the net to track the origins of the phrase. Poe's The Purloined Letter is the earliest example I know of the concept, though he doesn't ever use the phrase:

"At length my eyes, in going the circuit of the room, fell upon a
trumpery fillagree card-rack of pasteboard, that hung dangling by a
dirty blue ribbon, from a little brass knob just beneath the middle
of the mantel-piece. In this rack, which had three or four
compartments, were five or six visiting cards and a solitary letter...

"No sooner had I glanced at this letter, than I concluded it to be
that of which I was in search. To be sure, it was, to all appearance,
radically different from the one of which the Prefect had read us so
minute a description ...

"But, then, the radicalness of these differences ... were strongly
corroborative of suspicion, in one who came with the intention to
suspect."

Cryptographic lore contains a notion of hiding a message in plain sight, called steganography. One cute example of this is Spammimic, which will hide your treasured message in a faux spam email. Be careful if you use this, since spam is now under legal assault (and about time too).