Oh yeah I totally agree, I don’t know how to define personal data (and I didn’t mean to presume to state one), especially whenever it involves someone else, and I think you might be right about whether the property concept is useful. I also think it’s really problematic to aim for the ability to revoke information we’ve chosen to share publicly. This concept piece doesn’t quite say that explicitly, it says you should be able revoke access to your vault, and that there should be information that can only be accessed through the vault (not copied), so effectively adds up to enough control to make private information that was previously shared. Some people are getting the idea that information that has been made public (even by themselves) should be revocable. We’ve never had that ability in history before, and information that’s “public” falls outside the bounds of this paper (because public information can be legally copied). Still, it’s an interesting debate and I think we’re going to see these paradoxes start to resolve with better and better reasoning. I’m glad it’s being debated even if there’s no solution yet.