Chicago Tribune Sues Perplexity Over RAG and Paywalls

The Chicago Tribune has sued Perplexity, accusing the artificial intelligence search company of scraping and republishing its journalism without paying for it — and of even using paywalled stories to train its machine-learning systems.

The complaint says that the publisher’s lawyers inquired whether Squeeze and Perplexity used Tribune content; the company’s attorneys purportedly said it doesn’t train its models on the paper’s work but may surface non-verbatim factual summaries. The Tribune disagrees, saying Perplexity’s content is virtually word-for-word extracted from scraped stories.

The filing also goes after a product developed by Perplexity called retrieval-augmented generation, or RAG, arguing that the system relies on Tribune articles as a live data source and that the company’s Comet browser does an “end run around paywalls” to generate detailed write-ups. If proved, the case would not just challenge model training procedures, but also how AI services consume and serve copyrighted news at query time.

What the Chicago Tribune lawsuit against Perplexity alleges

Perplexity purports to users that it “synthesizes information responsibly,” despite actually lifting excerpts and structured information from Tribune reporting, the complaint says. The newspaper says its stories are being reproduced in ways that directly compete with the original articles, including behind-the-paywall content that is a cornerstone of subscription…