Third Circuit rejects ROSS fair-use defense in copyright case

The appeal arose from Thomson Reuters Enterprise Centre GmbH and West Publishing Corp. v. Ross Intelligence Inc., a dispute over copyright protection for Thomson Reuters materials and ROSS’s use of them.[1] The Third Circuit held that the materials were copyrightable and affirmed partial summary judgment for Thomson Reuters, concluding that ROSS’s use was not fair use.[1] The district court had ruled in February 2025 that ROSS infringed copyrights in 2,243 Westlaw headnotes and rejected its fair-use defense.[2]

ROSS’s AI was not generative; it returned text passages from preexisting judicial opinions.[1] The court said copying headnotes was an easy way to create those training memos, but was not necessary.[3] It also found that ROSS copied entire headnotes, taking more than was needed for a minimally transformative purpose.[2]

The court viewed ROSS’s use as only minimally transformative because its product used headnotes much as Westlaw did: to improve legal research.[3] FindLaw reported that three of the four deciding factors indicated ROSS’s use of the bulk memos was not fair use.[2] The Third Circuit identified potential harm to Westlaw’s existing legal-research market and to a developing market for licensing headnotes as AI-training data.[3] Westlaw has more than 28 million headnotes.[2]

The court emphasized that the case did not resolve whether training generative AI on copyrighted works is fair use, and described the dispute as no more than an ordinary copyright case.[3][1] ROSS had shut down in 2021, citing litigation costs, before pursuing its interlocutory appeal.[2] Thomson Reuters said it was pleased the appellate court affirmed the trial court’s decision in its favor.[4] ROSS’s counsel said the company disagreed, and ROSS said it intends to ask the U.S. Supreme Court to review the ruling.[5]