Perplexity hit with a lawsuit by two knowledge titans

By Trevor Mogg Published September 11, 2025

Perplexity is an AI-powered search tool that excels at delivering speedy and relevant answers in a conversational tone. But it’s now come up against two long-established giants of knowledge dissemination in the form of Encyclopedia Britannica and Merriam-Webster, which have hit it with a lawsuit.

Britannica and Merriam-Webster are accusing Perplexity of copyright infringement and trademark violation, Reuters reported on Thursday. They also claim that the San Francisco-based company has impacted their revenue by shifting web traffic away from their sites and to its own AI tool.

The case is the latest in a series of lawsuits targeting generative-AI companies like Perplexity and ChatGPT’s OpenAI, as well as larger outfits like Google, which is also building its own AI-powered tools.

While most of the lawsuit are about AI firms scraping content from the web to train their AI models without first getting permission from the copyright holders, the one targeting Perplexity is a little different as its AI tool searches the web in real time to gather data for its rapid and concise responses to users’ questions, eliminating the need for the user to visit the source’s website.

The suit, filed this week in New York federal court, says Perplexity’s AI tool “free rides” on Britannica and Merriam-Webster’s content and as a result is “cannibalizing traffic” to their websites as they rely on visits to sell subscriptions and earn revenue from ads.

Britannica and Merriam-Webster accuse Perplexity of infringing their copyrights by reproducing their content without permission. 

But that’s not the only issue. AI tools like Perplexity and ChatGPT are known to sometimes respond with erroneous information in what’s known as a “hallucination.” Some of Perplexity’s hallucinations are apparently attributed to Britannica and Webster’s content, which the accusers allege is a violation of their trademarks. 

The pair are requesting monetary damages from Perplexity. The amount hasn’t been revealed.  

Digital Trends has contacted Perplexity for a response to the legal action by Britannica and Merriam-Webster and we will update this article if we hear back.

This isn’t the first lawsuit to hit Perplexity. Media giant News Corp, for example, brought similar action in 2024, alleging copyright infringement by improperly using Dow Jones and New York Post articles in Perplexity’s online tool without permission. The case is ongoing.

The lawsuits against Perplexity, as well as others brought against similar companies, highlight the emerging legal challenges around generative AI, as well as the changing landscape of the internet, with publishers fearful of losing web traffic as users get the information they need from chatbots that are fueled by publishers’ content.

In a bid to create a fair and sustainable business model, many of the AI firms behind tools like ChatGPT and Perplexity have been seeking revenue-sharing deals with publishers. Perplexity also launched a program last month that offers to pay publishers a fee when its AI uses their content to answer questions.