联邦上诉法院裁定：Westlaw 判例摘要受版权保护，AI 拿去训练不算合理使用
美国联邦第三巡回上诉法院9月29日作出裁决，认定汤森路透（Thomson Reuters）旗下 Westlaw 法律数据库的判例摘要（headnotes）受版权保护，人工智能公司 ROSS Intelligence 拿这些摘要训练自家法律搜索引擎，不构成"合理使用"。这是美国联邦上诉法院首次就 AI 训练数据的合理使用问题作出裁决。
这场官司打了六年。汤森路透2020年起诉 ROSS，指控其未经许可使用 Westlaw 的判例摘要训练竞争性法律检索工具。ROSS 在2021年以诉讼成本过高为由关闭了业务。初审法院2025年已判汤森路透胜诉，第三巡回法院此次维持原判。
合议庭认定，ROSS 使用摘要的目的与 Westlaw 自身的用途基本相同，"转化性"极低；同时法院承认，判例摘要作为 AI 训练数据的授权市场正在形成——即使汤森路透目前并不向任何人授权这类使用。法院在脚注中特别区分：ROSS 的工具是非生成式 AI，与 Anthropic、OpenAI 相关案件中的生成式模型不同；且该裁决仅在第三巡回区有约束力。
几乎同一周，汤森路透在加州也被告上法庭。10月1日，加州卡尔斯巴德（Carlsbad）的 Rubin 律师事务所提起集体诉讼，指控汤森路透2023年以6.5亿美元收购法律 AI 公司 Casetext 属于"扼杀式收购"（killer acquisition）：Westlaw 自身没有生成式 AI，于是买下竞争者再将其并入更贵的 Westlaw 生态。诉状称，该律所的订阅费从每月32.5美元（Casetext）涨到每月111.48美元（Westlaw Classic），还签了三年期、每年涨价4%的合同。原告要求全国集体诉讼、三倍赔偿，并要求剥离或重建 Casetext。汤森路透对彭博法律表示尚未收到诉状，不予置评。
一边是法院确认法律内容护城河受保护，另一边是原告指控护城河变成垄断。法律科技媒体 LawFuel 评论道："内容为王，现在的问题是，这位国王要收多少钱。"
来源：LawFuel 2026年10月报道；Business Wire 2026年10月7日新闻稿。
Federal Appeals Court: Westlaw Headnotes Are Copyrightable; Using Them to Train AI Is Not Fair Use
On September 29, the U.S. Court of Appeals for the Third Circuit ruled that the headnotes in Thomson Reuters' Westlaw legal database are protected by copyright, and that AI company ROSS Intelligence's use of those headnotes to train a competing legal search tool does not qualify as fair use. It is the first federal appellate ruling on fair use in AI training.
The case has run for six years. Thomson Reuters sued ROSS in 2020, alleging it used Westlaw headnotes without permission to train a rival legal search engine. ROSS shut down in 2021, citing the cost of the litigation. The trial court ruled for Thomson Reuters in 2025, and the Third Circuit has now affirmed.
The panel found ROSS's purpose was essentially the same as Westlaw's own, making the use minimally transformative. The court also accepted that a market for licensing headnotes as AI training data is developing — even though Thomson Reuters licenses them to nobody. In a footnote, the court distinguished ROSS's non-generative tool from the generative models at issue in the Anthropic and OpenAI cases, and noted the ruling binds only the Third Circuit.
Almost the same week, Thomson Reuters was sued in California. On October 1, the Rubin Law Office of Carlsbad, California, filed a proposed class action alleging Thomson Reuters' 2023 purchase of legal AI company Casetext for $650 million was a "killer acquisition": Westlaw had no generative AI of its own, so it bought the challenger and folded it into the pricier Westlaw ecosystem. The complaint says the firm's subscription rose from $32.50 a month (Casetext) to $111.48 a month (Westlaw Classic), on a three-year contract with 4 percent annual increases. It seeks a nationwide class, treble damages, and an order to divest or re-establish Casetext. Thomson Reuters told Bloomberg Law it had not been served and could not comment.
One court says the content moat behind Westlaw is protected property; one complaint says the business built on it is a monopoly. As legal-tech outlet LawFuel put it: "Content is King. The question now is how much the king gets to charge."
Sources: LawFuel, October 2026; Business Wire press release, October 7, 2026.
图片来源：图：联邦第三巡回上诉法院所在的费城詹姆斯·A·伯恩联邦法院大楼。摄影：ajay_suresh，CC BY 2.0，来源：Wikimedia Commons
