> Maybe it's like somebody mining for diamonds under my house - they've found some value in something I didn't know I had, but I now want my share.

And this is one of the harder parts of assigning value to something like this... What is a person's share when someone exploits a resource that the first party had some kind of nominal claim to (i.e. "my land," even though really you live above that 3D region of space, not within it) but zero ability / opportunity / inclination to exploit?

There's volumes and volumes of legal precedent on this topic for tangibles, let alone the increasingly-intangibles that we can monetize online.