Comment by otterley

I think the court dropped the ball here. On the one hand, I think they were right that using existing works--copyrighted or otherwise--to train a model was transformable fair use. On the other hand, Anthropic and others trained their models on illicit copies of the works; they (more often than not) didn't pay the copyright holders.

There's a doctrine in Fifth Amendment law called "fruit of the poisonous tree." The general rule is that prosecutors don't get to present evidence in a criminal trial that they gained unlawfully. It's excluded. The jury never gets to see it even if it provides incontrovertible evidence of guilt. The point is to discourage law enforcement from violating the rights of the accused during the investigative process, and to obtain a warrant as the Amendment requires.

It seems to me that the same logic ought to be applied to these companies. They want to make money by building the best models they can. That's fine! They should be able to use all the source data they can legitimately obtain to feed their training process. But if they refuse to do so and resort to piracy, they mustn't be allowed to claim that they then used it fairly in the transformative process.