Just to say the obvious, the idea that it's unethical to distill from AI models, but totally ethical to train on copyrighted source material is … definitely a take that the frontier labs have encouraged.

Fair point. But Meta also has a vested interest in keeping terms of service strong, so it wouldn’t really do for them to violate Anthropic’s and then go to court over it. Meta would then be in a lose-lose scenario, all over an open weight model that is a money sink to begin with.