NORTHAMPTON — Alleged theft of thousands of copyrighted articles, used to train artificial intelligence programs ChatGPT and Microsoft Copilot, is at the center of a civil lawsuit the company that owns the Daily Hampshire Gazette has joined against OpenAI and Microsoft.

The 55-page lawsuit, filed June 24 in Manhattan federal court, argues the technology giants took copyrighted content without permission, causing significant harm to the local journalism industry.

“This lawsuit arises from defendants’ systematic and willful theft of hundreds of thousands of copyrighted articles belonging to the publishers, who collectively own and operate nearly 400 local and regional newspaper outlets across the country, all of whom have spent decades — and in some cases over a century — investing in the journalists, editors, and infrastructure required to produce the trusted, original reporting on which their communities depend,” the publishers wrote in their civil complaint.

Newspapers of New England, which also owns the Concord Monitor, Valley News and Monadnock Ledger-Transcript in New Hampshire as well as three Massachusetts newspapers including the Greenfield Recorder and Athol Daily News, is among a group of print and digital publishers that are parties to the suit.

The coalition is represented by Matthew J. Platkin, former attorney general of New Jersey. The civil suit claims OpenAI and Microsoft took original news content to build their artificial intelligence products, violating the Copyright Act.

“The publishers’ journalism was essential to the defendants’ explosive growth, and unless defendants are held accountable for stealing, stripping and misusing the publishers’ content, the AI boom defendants orchestrated and benefit from will be a death knell for local journalism — which remains the most trusted news sources in America,” the publishers wrote.

The publishers claim OpenAI and Microsoft “systematically and secretly crawled” hundreds of news websites, including content behind paywalls and other access restrictions, to copy articles and other original works onto their own servers without authorization.

Then, information such as the names of authors, publication and terms of use information and copyright notices were removed. The technology companies are accused of using this stripped content to train their artificial intelligence large language models, which “memorized” that material and likely reproduced it, verbatim or near-verbatim, in response to user prompts for years.

The lawsuit adds that ChatGPT and Microsoft Copilot have generated hundreds of billions of dollars, yet “not a cent of it has gone to the publishers whose work made it possible.”