California AI Data Disclosure Law Heightens Developer Legal Risk

A new California law that requires AI companies to be more transparent on the data they use could have far-reaching effects, attorneys said, such as curbing open-source development in the sector.

California has the nation’s most comprehensive rules on AI training data after Gov. Gavin Newsom signed legislation (AB 2013) on Sept. 28. The law—which takes effect in 2026—covers startups to large tech giants like OpenAI Inc. and Meta Platforms Inc. that produce generative AI, the type that uses human prompts to create text, images, and similar content.

Training data, which can include everything from social media photos ...