> Proprietary model weights are IP

Not copyrightable IP, or at least it hasn't been challenged yet. I have experience with this: I made llama-dl, a way to download the original llama model. Meta issued a DMCA, I appealed to the HN community for funds, someone funded, and our lawyer successfully counterclaimed. Never heard from Meta again.

A lack of response to the counterclaim doesn't mean the issue is settled. But now there's legal precedent for people pushing back against companies that claim model weights are secret IP and therefore DMCA-able.

I do wonder if their "fair use" argument preempts them from actually being able to claim copyright over the model weights, since it can be argued that the vast majority of what the model is is itself a remix of everything else. Maybe their RLHF, system prompts, architecture and training techniques can be considered copyrightable, but maybe most of the data can't.