Indeed. I think it's very hard to draw, I'm afraid. I think there are some things -- which is perhaps why we're here. There are some things I can say about this. One is that the distinction between the public and the private might be one useful way to draw it, and I think I said in my written submission that I think there's room for a lot more work, philosophical work, on when something's an appropriately public matter and when it's a private matter. But I have quite clear intuitions about some cases. I don't know quite what line underlies them but here's an example.
Say interest in the health of a politician's child. In many contexts, I think that might be considered a private matter that shouldn't be a matter for -- shouldn't enter the public sphere. Perhaps not in every context, but in many contexts it should be. Contexts where it could enter the public sphere might be cases where revealing this health issue would reveal hypocrisy on the part of a politician or is relevant to particular policies a politician is pursuing, but perhaps unhelpfully for you, I think it's rather hard to draw a clear line.