Condé Nast issued a cease-and-desist letter to Perplexity AI accusing the start-up of plagiarism and demanding it stop using content from its publications in its AI-generated responses. 

Perplexity has been criticised for not respecting the Robots Exclusion Protocol, which is used by websites to block bots from scraping their content. Investigations revealed that Perplexity's web crawlers continued to access restricted content, raising ethical and legal concerns. 

The move is part of a broader trend among major publishers, including The New York Times, The Guardian, and Forbes, who have blocked Perplexity's crawlers from accessing their content due to concerns over copyright infringement and potential loss of ad revenue.

Condé Nast's actions highlight the growing tension between AI companies and content creators over the use of copyrighted material, emphasising the need for clearer regulations and guidelines in the evolving AI landscape.