Out Of The Shadow Library: Fair Use And AI Training Data

Since the launch of the first Large Language Models (LLMs), a wave of copyright litigation has been initiated by authors, musicians, and news organizations alleging that their works were misappropriated to build today's most powerful generative AI tools. In response, AI companies have asserted that such use is non-infringing fair use. These lawsuits target a spectrum of alleged copyright infringement. Some lawsuits focus solely on the unauthorized use of works as training inputs, others focus on the model's ability to generate allegedly infringing outputs, and many premise liability on both behaviors.

In 2025, two rulings offered the first judicial perspectives on one end of this spectrum: whether unauthorized use of copyrighted works as training "inputs" constitutes fair use. While the outcomes of these cases have been widely reported—both rulings suggest training generative AI models on copyrighted works may be fair use—the legal landscape is far from