Mark Zuckerberg is facing criticism after Facebook censored one of the most famous war photographs in history.
The editor of a top Norwegian newspaper on Thursday addressed an open letter to Zuckerberg saying he was "upset, disappointed -- well, in fact even afraid" over the impact of Facebook algorithms on media freedom.
Espen Egil Hansen said his newspaper, Aftenposten, received a demand from Facebook on Wednesday to remove the iconic Vietnam War photo of a naked girl fleeing a napalm attack.
"Less than 24 hours after the email was sent, and before I had time to give my response, you intervened yourselves and deleted the article as well as the image from Aftenposten's Facebook page," Hansen wrote.
His complaint highlights growing concern about Facebook's vast and expanding influence over news and other content seen by more than a billion people around the world.
"You create rules that don't distinguish between child pornography and famous war photographs," Hansen wrote to Zuckerberg. "Then you practice these rules without allowing space for good judgment."
Facebook said it recognizes that the photo is iconic, but stressed that it's "difficult to create a distinction between allowing a photograph of a nude child in one instance and not others."
"We try to find the right balance between enabling people to express themselves while maintaining a safe and respectful experience for our global community," the company said. "Our solutions won't always be perfect, but we will continue to try to improve our policies and the ways in which we apply them."
The saga began when Norwegian author Tom Egeland posted a series of historic war photographs on Facebook.
The social network then removed one of the images -- the famous Vietnam photo of the naked girl, Kim Phuc, fleeing the napalm attack -- and later suspended Egeland's account after he posted a reaction to the deletion, according to the Norwegian newspaper.
When Aftenposten shared its article on Facebook about what happened to Egeland, that too fell foul of the platform's rules.
"You even censor criticism against and a discussion about the decision -- and you punish the person who dares to voice criticism," Hansen wrote.
The dramatic photo, snapped by Associated Press photographer Nick Ut, won a Pulitzer Prize and is one of the most memorable images of the 20th Century. Despite its graphic nature, the publication of the photo has been credited with helping to turn U.S. public sentiment against the war in Vietnam.
Hansen told CNNMoney's Nina Dos Santos on Friday that Zuckerberg is now "the most influential editor-in-chief in the world."
"With that follows a great responsibility," Hansen said. "I ask him to think through what he is doing ... to the public debate all over the world."
Rolv Erik Ryssdal, chief executive of the media house that publishes Aftenposten, said in a statement that Facebook's position "is not acceptable" and constitutes an attack on democracy and freedom of expression.
Zuckerberg has tried to fend off pressure about Facebook's role in managing what articles and images people see.
"We're a technology company, we're not a media company," he said last month. "We do not produce any of the content."
But some media experts disagree.
"Whether intentional or desired or not, Facebook does now play a critical role in the distribution of news," Jeff Jarvis, a journalism professor at the City University of New York, wrote in a blog post earlier this year. "An editor -- or perhaps an ethicist-in-chief -- could help set the services standards and policies."
Jarvis seized on the Norwegian editor's letter to Zuckerberg, tweeting that it's an example of "exactly why I keep suggesting Facebook needs a top level journalist."
Facebook was engulfed by controversy in May over how news stories were chosen for its "trending topics" box. Last month, it removed the humans responsible for manually writing news descriptions and headlines for the section, turning the job over to software programs.