I'm thinking of this line from the Hippocratic Oath, which I understand to be quite historical:

"Whatever, in the course of my practice, I may see or hear (even when not invited), whatever I may happen to obtain knowledge of, if it be not proper to repeat it, I will keep sacred and secret within my own breast."

The point is that this isn't being challenged in the latest privacy wars, even though it flies straight in the face of the completely nonsense mantra of "if you've nothing to hide...."