It's hard to regulate the users' ignorance or to prevent the use of awful dark patterns like "public by default."

But it would be a more ethical world if every site with public-facing social features had to create something like the presentation that publicbydefault.fyi has put together here. Something that graphically exposes the exact privacy implications of the data people are leaking. Privacy is at this point an educational problem as much as a technical problem, and it's on us to figure out the best practices for how to teach it.