A law like this could only apply to websites operating at a certain scale, exceeding some revenue threshold, owned by publicly traded companies, or some other p

A law like this could only apply to websites operating at a certain scale, exceeding some revenue threshold, owned by publicly traded companies, or some other proxy to get only the sites we’re talking about here. This is just off the top of my head too, I’m sure much smarter people can craft a framework much better than OP’s which is already a very good one.