I know data is probably cached, shit even if not by design, you could make it go into a page file and at that point it's "on the hdd", for that matter, you could capture it directly from RAM. I was just trying to make my answer simpler because this is still a massive magnitude greater in complexity than all the files simply being installed, and we're talking about a potential future where they clamp down on this. The game can be made in a way that it becomes very difficult to both crack and mod it to use all the piecemeal files you'd collected because it doesn't automatically load cached files, it expects doses of them, maybe even with changing hashes/identifiers because the DRM was baked into how it works. Nothing is ever impossible and anything can be modded, but they can make this a nightmare.