The New York Times sued ChatGPT-maker OpenAI and Microsoft in a US court yesterday, alleging that the companies' powerful AI models used millions of articles for training without permission.

Through their AI chatbots, the companies "seek to free-ride on The Times's massive investment in its journalism by using it to build substitutive products without permission or payment," the lawsuit said.

With the suit, the New York Times chose a more confrontational approach to the sudden rise of AI chatbots, in contrast to other media groups such as Germany's Axel Springer or the Associated Press that have entered content deals with OpenAI.

The Times, one of the most respected news organizations in the United States, is seeking damages, as well as an order that the companies stop using its content -- and destroy data already harvested.

Microsoft is a major investor in OpenAI, and swiftly implemented the powers of AI to its own products after the release of ChatGPT last year.

The AI models that power ChatGPT and Microsoft's Copilot (formerly Bing) were trained for years on content available on the internet, under the assumption that it was fair to be used without need for compensation.

But the lawsuit argued that the unlawful use of the Times' work to create artificial intelligence products threatened its ability to provide quality journalism.

"These tools were built with and continue to use independent journalism and content that is only available because we and our peers reported, edited, and fact-checked it at high cost and with considerable expertise," a spokesperson for the Times said.

The emerging AI giants are facing a wave of lawsuits over their use of internet content to build their AI systems.

Last year "Game of Thrones" author George RR Martin and other best-selling fiction writers filed a class-action lawsuit against OpenAI, accusing the startup of violating their copyrights to fuel ChatGPT.

Universal and other music publishers have sued artificial intelligence company Anthropic in a US court for using copyrighted lyrics to train its AI systems and in generating answers to user queries.

With lawsuits piling up, Microsoft and AI player Google have announced they would provide legal protection for customers sued for copyright infringement over content generated by its AI.