The Huffington Post was sued on Tuesday by a freelance journalist claiming unpaid bloggers should be compensated for the value they created for the website, which AOL bought for $315 million.
Jonathan Tasini, the lead plaintiff in the suit filed with a US District Court in New York, is demanding at least $105 million in damages for The Huffington Post's uncompensated writers and other content providers.
Tasini is seeking to have the suit accepted as a class action representing more than 9,000 writers and others who contributed material to The Huffington Post for free since it was launched six years ago.
The complaint against Huffington Post co-founders Arianna Huffington and Kenneth Lerer, along with new owner AOL accuses The Huffington Post of deceptive trade practices and unjust enrichment.
It charges that unpaid bloggers created substantial value for The Huffington Post, leading to its eventual purchase in February by AOL.
"In Huffington's business model, economic gain is only reserved for her," Tasini said in a statement. "Everyone else, apparently, is expected to work for free regardless of the value they create."
Tasini counsel Jesse Strauss said his team intends to prove at trial that "the content and services provided by the over 9,000 members of the class created substantial value for the Huffington Post and we hope to establish a strong precedent that in the digital age, content producers must be compensated for the value they create."
Huffington Post spokesman Mario Ruiz dismissed the lawsuit as "wholly without merit."
"As we've said before, our bloggers use our platform - as well as other unpaid group blogs across the Web - to connect and help their work be seen by as many people as possible," Ruiz said.
"It's the same reason people go on TV shows: to promote their views and ideas... Aside from our group blog, to which thousands of people from around the world contribute, we operate a journalistic enterprise with hundreds of paid staff editors, writers and reporters."
The Newspaper Guild, a union of US media workers with 26,000 members, urged Huffington Post contributors last month to stop providing free content to the news and opinion website.
The Huffington Post has attracted a strong following - nearly 25 million unique visitors a month - to its lively mix of news, entertainment, opinion and blogs submitted by academics, entertainment figures, politicians and others.