The Chicago Tribune filed a lawsuit against AI search engine Perplexity on Thursday, alleging copyright infringement and unauthorized use of its content. The complaint, filed in federal court in New York, claims Perplexity delivers Tribune content verbatim and uses the material in its retrieval-augmented generation (RAG) systems without permission. The suit also asserts that Perplexity’s Comet browser bypasses the Tribune’s paywall to provide detailed article summaries.
Perplexity’s lawyers reportedly told the Tribune in October that their models do not train on the newspaper’s work, though they may produce “non-verbatim factual summaries.” The Tribune disagrees, arguing that RAG methods are still using copyrighted material. The lawsuit follows similar legal action against other AI developers; in April, MediaNews Group and Tribune Publishing sued OpenAI and Microsoft over model training material. Additional suits from the same publishers have been filed since.
Perplexity has faced other legal challenges, including from Reddit and Dow Jones, while Amazon has sent a cease-and-desist letter over AI scraping. On the other side, the company is pursuing high-profile expansion and partnerships, most recently naming Cristiano Ronaldo as an investor and global partner.
