Press Release

Reminder on Class Eligibility Requirements in Bartz v. Anthropic AI case

As publishers and authors consider developments in the Anthropic case, it’s important to understand that Judge Alsup defined class eligibility requirements in his July 17, 2025, class certification decision.

In sum, the court’s definition provides criteria that significantly narrow the universe of works that will be eligible for recovery, in contrast from the previously reported seven million works that may be residing on pirate sites but will not be at issue before this court in this case.

As defined by Judge Alsup, the class in this case is limited by when Anthropic downloaded works from LibGen and PiLiMi, and when the works were published and registered.

As a bright line rule, any work published or registered after July 2022 is definitively outside the class, and for some works the cutoff is June 2021. 

See more detail below for the criteria for works that meet the class definition, taken from page 31 of the class certification decision.

• The beneficial or legal owners of the exclusive right to reproduce copies of any book downloaded by Anthropic (1) through Library Genesis (LibGen) in June 2021, or (2) through Pirate Library Mirror (PiLiMi) (which is a mirror site of Z-Library) in July 2022.

• “Books” here means any work (1) possessing an ISBN or ASIN, that was (2) registered with the U.S. Copyright Office (a) within five years of the work’s publication and (b) prior to being downloaded by Anthropic or within three months of publication.