The best analogy for this I've seen is this: it's no secret that everybody poops. But that doesn't mean everyone likes having other people watch while they do it (privacy).
If they truly have no ethical or moral boundaries, then they are probably deviant enough that they won't be able to get into a position to set much policy, anyways, by definition of their lack of fitness to represent the majority of any population.
You go ahead and zen out and, in turn, take those things with grace by going along with it when someone raises a fuss ("oh, I am soooo humiliated! :)"). Or if you're of another archetype, you'll find witty ways to playfully snap back and turn it around on people trying to clown on you (alas, I'm not of this type/talent). Moreover, there are the countless, other not-uncommon approaches that often lead to escalation/hostility/violence.
Then it becomes a drag (and where the issue lies) when it really catches on in wildfire manner, to where it will have practically problematic effects on you personally or professionally, not unlike the lie that makes it halfway 'round the world before the truth can put its pants on.
As far as I see it, all of that is what is trying to be highlighted with the pooping witness analogy. Of course, that should probably be underscored when presenting it.
You'll probably still get a "yeah, that's fine" or "I don't care what anyone else thinks" after you elaborate. And tons of other cans of worms can reasonably be opened as topical offshoots; I'm just trying to concur that the "I don't mind" response doesn't really feel like a response.
Maybe some people even think they believe it when they say it, but I've yet to see anyone who is willing to demonstrate it when pressed, and I've even met a few people who have claimed that they have no concerns at all about their privacy, but who then ended up feeling violated when even small things they assumed were private ended up being exposed.