Overview

• Encyclopaedia Britannica and Merriam-Webster filed a federal complaint in the Southern District of New York accusing Perplexity’s “answer engine” of unlawfully using their content.
• The suit alleges copyright infringement for copying protected works as both inputs and outputs and claims false designation of origin and trademark dilution.
• Plaintiffs cite examples including Perplexity returning the exact Merriam-Webster definition of “plagiarize” and alleged hallucinated content wrongly attributed to their brands.
• The complaint seeks unspecified monetary damages and an injunction to block Perplexity’s use and misattribution of their materials.
• The case joins a broader wave of publisher actions against Perplexity, following Dow Jones and New York Post lawsuits that survived a motion to dismiss in August and new filings by Japan’s Nikkei and Asahi Shimbun.