Well, a larger issue seems to be that this whole idea is premised on taxing an unrealized gain. If I create a painting, I don't owe any taxes on it until I sell it. If the world decides that I'm Picasso and my sneezing on a canvas means it's worth $50 million, it still won't be true that, after I sneeze without covering my mouth and some spittle lands on one of my blank canvases, a government official shows up to my house to force me to sell it so that I can pay the taxes I owe for creating it.