A federal district court judge in Delaware issued the first major ruling on whether using copyrighted materials to train artificial intelligence systems constitutes copyright infringement. On Feb. 11, Judge Stephanos Bibas granted a summary judgment to Thomson Reuters, which makes the legal research service Westlaw, against a company named Ross Intelligence. The judge found that Ross infringed on Reuters’ copyrights by using Westlaw headnotes — essentially case summaries — to train its own legal research AI.