It’s preety simple as I see it. You treat AI like a person. A person needs to go through legal channels to consume material, so piracy for AI training is as illegal as it would be for personal consumption. Consuming legally possessed material for “inspiration” or “study” is also fine for a person, so it is fine for AI training as well. Commercializing derivative works that infringes on copyright is illegal for a person, so it should be illegal for an AI as well. All materials, even those inspired by another piece of media, are permissible if not monetized, otherwise they need to be suitably transformative. That line can be hard to draw even when AI is not involved, but that is the legal standard for people, so it should be for AI as well. If I browse through Deviant Art and learn to draw similarly my favorite artists from their publically viewable works, and make a legally distinct cartoon mouse by hand in a style that is similar to someone else’s and then I sell prints of that work, that is legal. The same should be the case for AI.

But! Scrutiny for AI should be much stricter given the inherent lack of true transformative creativity. And any AI that has used pirated materials should be penalized either by massive fines or by wiping their training and starting over with legally licensed or purchased or otherwise public domain materials only.