people have talked about context collapse before, where your internet presentation isn't able to be segmented into what you'd show church people, employers, peers, family, etc., and it's all just one context
but of course we know that in practical terms, people don't *use* social media as if the context were absolutely everyone in their lives seeing it. that's why it's always awkward when a Bad Tweet goes viral and it's clear the tweeter was using Twitter to chat within their social network, with a thicker context, where more subtle ironies and such might be expressed.... but actually they were posting publicly also
my theory is that there's something particularly psychologically stressful about having to deal with Schrodinger's Audience: when you put something out there, you have to adopt a tone of humility appropriate to only a few people, maybe your close contacts seeing it... but you also have to communicate as though you might be talking to Absolutely Everyone. and you don't really control which.
this seems *different* somehow than the long-feared "but what if my boss sees my weekend partying". that's someone outside the intended audience seeing it. instead it's about... not even clearly intending an audience to communicate to, I guess, because of how stochastic it all feels