Earlier last week, a pivotal US ruling regarding fair use in AI-related copyright litigation was delivered by Judge Stephanos Bibas in the case Thomson Reuters v. ROSS Intelligence. Background Thomson Reuters is the owner of Westlaw, one of the largest and most widely used legal research platforms in the US. Subscribers gain access to an extensive range of legal resources, such as case law, statutes, regulations, news, law review articles, and more. ROSS Intelligence, a competitor, sought to license Westlaw’s content for its own legal AI tool. When Thomson Reuters refused, ROSS acquired “Bulk Memos”—which were created using Westlaw’s headnotes—through a third-party legal services vendor. Upon discovering this, Thomson Reuters filed a lawsuit against ROSS for copyright infringement based on its use of Westlaw content to train its AI model. The court granted partial summary judgment in favor of Thomson Reuters. The case was analyzed under the fair use framework established by the US Copyright Act. The court found in favor of Thomson Reuters on the first factor, "the purpose and character of use." In assessing ROSS’s use, the court determined that it was commercial in nature. Although ROSS argued that its use was transformative—since it allegedly “transformed” headnotes into numerical data for its AI system—the court disagreed. The second factor: the nature of the copyrighted work. The court sided with ROSS, finding that although Westlaw’s content has some originality, it is not highly creative. The court ruled in ROSS’s favor on the third factor, the amount and substantiality of the portion used in relation to the copyrighted work. Despite the number of headnotes used, since the material was not publicly available and did not include the headnotes from Westlaw. The most critical aspect of the case came with the fourth factor, the likely effect of the use on the market for the original work the court. The court ruled that ROSS could have developed its own product without infringing Thomson Reuters’ copyrights. The key takeaway for AI developers and deployers is this: they must closely monitor the ongoing litigation surrounding AI and copyright, keeping an eye on how fair use will be applied to both training models and AI-generated output. Given the facts-driven nature of fair use, courts are likely to issue different rulings based on the specifics of each case, particularly where commercial use is involved.
