Our Blog

Here’s What Happened:

Westlaw (owned by Thomson Reuters) gives attorneys handy headnotes and a key system for legal research. The headnotes summarize and organize a judge’s opinion so that an attorney can, at a glance, determine the relevance of a court’s opinion. Thomson Reuters owns the copyrights to the headnotes.

Ross Intelligence Inc. used an artificial intelligence training model to copy Westlaw’s headnotes in order to create its own legal research database.

Thomson Reuters sued Ross for copyright infringement. Ross asserted several defenses including fair use. Both sides moved for summary judgment.

Initially, the trial court denied both motions. However, upon reconsideration, the court determined that Ross Intelligence had infringed on Thomson Reuters’ copyrights.

In addressing the four factors of fair use, the court found that two factors weighed heavily against fair use.

1. First Factor; Character of the Use: Ross used the headnotes to create for profit legal research services. Ross argued that its use was transformative enough to weigh this factor in its favor. But, Ross couldn’t point to a strong justification for copying. So, court held that Ross’s use was not transformative because it “was using Thomson Reuters’s headnotes as AI data to create a legal research tool to compete with Westlaw.”
2. Fourth Factor; The Effect the Use Has on the Market: The court considered this the most important factor. The court held that Ross’ product posed a direct threat to Thomson Reuters’ market.

The court granted Thomson Reuters’ motion for summary judgment.

WHY YOU SHOULD KNOW THIS: AI is here to stay in many contexts and industries. It’s functions and uses are ever evolving. Courts will have to grapple with reconciling copyright law  and AI’s unauthorized access to copyrighted material.

Cited Authority: Thomson Reuters Enterprise v. Ross Intelligence Inc, 1-20-cv-613-SB (D,Ct. Del., February 11, 2025).