Anthropic to pay $1.5 billion（約2400億円） to settle author piracy lawsuit over Claude training

This settlement represents a watershed moment for AI copyright liability. While U.S. District Judge William Alsup's earlier ruling protected the core practice of training AI models on copyrighted text—classifying it as fair use—his mixed decision also flagged a critical distinction: the legality of the training method depends on how the company acquired the training data in the first place. Anthropic's use of pirated copies obtained from pirate websites fell outside that protection, leaving the company exposed to damages.

The $1.5 billion（約2400億円） settlement, the first major recovery in what plaintiff counsel described as a class-action addressing copyright infringement at scale, signals that AI companies cannot simply treat pirated content as a cost-effective shortcut to assembling training datasets. The fact that over 91% of affected authors and publishers have claimed their shares suggests broad awareness and participation in the recovery process. With dozens of similar AI copyright lawsuits still pending in courts, this precedent—that fair use may protect the training act itself but not the method of data acquisition—is likely to shape how future defendants negotiate settlements and how courts weigh comparable claims.