Facebook has come under criticism for censoring a news article on mammograms due to an image of a woman's exposed breast. The company apologized for removing the post and restored it late Tuesday, though the incident adds to an ongoing controversy over a moderation policy that some have described as sexist.

The article, published Tuesday by Les Décodeurs, a data-focused website run by the French newspaper Le Monde, reported on a recent government initiative to overhaul mammogram screening in France. Its lead image showed a woman undergoing a mammogram, with one of her nipples exposed. Facebook removed the article shortly after it was posted to Les Décodeurs' page, apparently because the image of a nipple violated the company's community standards.

"Thank you Facebook for fighting every day against the breast," Samuel Laurent, a Le Monde journalist, wrote on Twitter Tuesday.

Facebook's community standards prohibit users from posting nude photos or sexually explicit content, though the site says it makes exceptions for "photos of women actively engaged in breastfeeding or showing breasts with post-mastectomy scarring." Facebook has faced criticism in recent years for aggressively enforcing its nudity policy, which has been used to censor paintings, awareness campaigns, and, most recently, an iconic Vietnam War photo. The site briefly removed an image of a woman undergoing a mammogram in 2015, before restoring it and issuing an apology.

Les Décodeurs, which has more than 71,000 Facebook followers, reposted the article to its page on Tuesday afternoon, replacing the previous photo with an image of a man's bare torso. A blurb overlaying the photo explains that after Facebook "censored" the original image, the website "replaced it with an image of a nude torso of a man, which, itself, does not violate" the site's terms of service. (The original photo remains the article's lead image on the website.)

In a statement, Facebook apologized for removing the post from Les Décodeurs, and restored it late Tuesday. The company said that it makes exceptions for images that raise awareness around mammograms, in addition to those of mastectomy scars and breastfeeding, though mammograms are not explicitly mentioned in its community standards.

“The post was removed in error and restored as soon as we were able to investigate," a Facebook spokesperson said. "Our team processes millions of reports each week, and we sometimes get things wrong. We're very sorry about this mistake.”

Michaël Szadkowski, editor-in-chief of Le Monde's website, declined to provide additional comment on the post when reached by The Verge; but the text overlaying the new image clearly points to a double standard that activists have described as sexist. Last year, female Instagram users posted topless photos of themselves with male nipples superimposed on their breasts as part of the Free the Nipple campaign, which seeks to destigmatize bare breasts. (Instagram, which is owned by Facebook, has a nearly identical policy on nudity.)

"Facebook prefers xenophobic comments it's well known!!"

Other critics have argued that Facebook polices nudity more aggressively than hate speech or xenophobic content. Last year, a German photographer launched an online protest with a photo of a topless woman standing next to a man holding a sign with a racial slur on it. "One of these people is violating Facebook's rules," the photo's caption read. Commenters made similar arguments on the post from Les Décodeurs, with one writing: "Ah Facebook prefers xenophobic comments it's well known!!"

"Facebook's reporting tools conflate nudity with sexuality," Jillian York, director for international freedom of expression at the Electronic Frontier Foundation (EFF), said in an email, adding that the social network only prompts users to say whether an offending post contains "nudity or pornography." York herself was banned from Facebook for 24 hours earlier this year for posting an image from a German campaign on breast cancer awareness, which used photos of bare-breasted women to encourage self-checking.

"It may be reasonable of Facebook to, for example, ban pornography, but I await the company's justification for specifically banning female nipples, particularly in non-sexual contexts," York said. "Imposing a blanket ban on nudity, even if a handful of exceptions are carved out, furthers the idea that women's bodies are inherently sexual."