The US District Court for Delaware ruled in favor of Thomson Reuters, finding that ROSS Intelligence infringed Westlaw’s copyrights by using its headnotes and editorial content for AI training. The Court rejected ROSS’s fair use defense, emphasizing market harm and the need for AI developers to license copyrighted materials. While granting partial summary judgment to Thomson Reuters, the Court left certain copyright expiration claims for jury determination. This decision reinforces copyright protections in legal research and sets a precedent for…