The 3rd US Circuit Court of Appeals has ruled in favour of Thomson Reuters on the two primary issues in its long-running copyright fight with ROSS Intelligence, the now-shuttered artificial intelligence legal research company.
Those issues were the copyrightability of Westlaw's headnotes, and fair use. The court found for Thomson Reuters on both.
That makes it the first federal appellate decision to address fair use in the context of AI training, a question with a queue of litigation behind it.
The opinion itself remains under seal, while the court allows the parties to request redactions. What is known is that the panel entered judgment affirming Judge Stephanos Bibas's February 2025 summary judgment for Thomson Reuters. The day before, the existence of an opinion was public but its contents were not viewable by anyone.
The two questions on which the lower court granted summary judgment were narrow and consequential. First, whether a short quote or paraphrase of a judicial holding can be copyrightable. Second, whether fair use protected ROSS's internal use of Westlaw headnotes as training data for an AI legal-search engine whose outputs themselves did not infringe.
Judge Bibas had found that Westlaw's Key Number system and more than 2,200 headnotes were original enough to be protected by copyright, and having found that, rejected ROSS's fair-use defence.
ROSS built its legal search platform in 2015 by adapting headnotes into questions and using them to create training material for a system that could connect natural-language legal questions to judicial opinions.
Several features of the case limit how far it reaches. The copying predated the widespread popularity of generative AI and was carried out for a non-generative system; Judge Bibas found it was done to build a product designed to compete directly with Thomson Reuters; and this was an interlocutory appeal from a summary judgment order. Whether the ruling is narrowly confined or announces a broader rule will not be known until the reasoning is released.
A Thomson Reuters spokesperson told Reuters that the company was pleased with the ruling and "firmly believes that respecting copyright is essential for fostering innovation while protecting the intellectual property that fuels fiduciary-grade AI solutions".
The question the court has now answered is whether a short summary of what a court decided is original enough to belong to whoever wrote it. The answer, so far as anyone can establish, is yes.
This places the ruling in an unusual position. It is a document whose central finding is that writing down what a court has held creates a new work owned by its author. It is also a document that nobody is permitted to read.
The sequence after unsealing can be predicted with some confidence. An editor will read the opinion and write a headnote summarising what it held. Under the rule the opinion itself establishes, that headnote will be original enough to be protected, and the only authorised short description of the law on copying short descriptions of the law will be owned by a publisher.
The seal, on this reading, is not an obstruction but a demonstration. For as long as it holds, the leading authority on whether material may be copied in order to learn from it is protected from copying by the most reliable method known to law, which is that it has not been published.
The Department of Unnecessary Research notes that the position is logically stable and requires no further action by the court. The law on reading in order to learn is currently unreadable, and anyone wishing to know what it says will have to summarise it, which is the activity at issue.
The court has settled what may be copied. It has not yet released a copy.