"Privacy" as formulated in 2015 is frankly a fairly modern concept. As much as people seem to assert "we used to have privacy" I suspect it was about as real as the 'Father Knows Best' prototypical TV family - ie not really.
For the bulk of human existence, we have lived in small family or clan groups. This meant that everyone not only knew everything about you, but (usually) everything about everyone you were related to, and your ancestors. Had a crazy g'great grandfather that got caught cheating on his wife? Everyone knows, and likely expects that you're not terribly faithful either. Mother was a drunk? Everyone knows, and expects you're probably a drunk too. You said bad things about the clan chief, odds are eventually he knew. You were not only responsible for what you said or believed, you were frequently called to account for it (fairly or not).
Privacy - the very concept of anonymity - was extraordinarily limited until literacy was widespread, and even then the idea that you'd write something and nobody knew who wrote it was ridiculous really until the printing press, and even then the number of people involved meant your risk of discovery probably was a steeper curve than your audience breadth until the modern era, and small-shop copy machines/mimeographs.