I always thought this was an interesting thought exercise just conceptually (not even legally.) If you and I are friends, is the knowledge of that friendship m

I always thought this was an interesting thought exercise just conceptually (not even legally.) If you and I are friends, is the knowledge of that friendship mine? Is it yours? Can I freely share that knowledge with someone else? The impact of this just became so absurdly large when we started saving those data points forever and mining them for all sorts of purposes they weren't originally intended for.