Facebook has come under criticism for censoring a cancer awareness video because of animated breasts. The ad campaign, produced by Cancerfonden, a Swedish cancer charity, used animated figures to demonstrate how to conduct breast exams. Facebook removed the video this week, telling the organization: "Your ad can not market sex products or services nor adults products or services," according to The Guardian. The social network later apologized.

"We’re very sorry, our team processes millions of advertising images each week, and in some instances we incorrectly prohibit ads," Facebook said in a statement to The Guardian. "This image does not violate our ad policies. We apologize for the error and have let the advertiser know we are approving their ads."

Facebook has repeatedly faced criticism for aggressively enforcing its ban on nudity and sexual content. Earlier this month, the company removed a news article about mammograms because of an accompanying image that showed a woman undergoing the procedure; and in September, Facebook censored an historic image from the Vietnam War because it depicted a naked girl fleeing a napalm attack.

The site has censored illustrated depictions of breasts, as well, including a cartoon from The New Yorker in 2012. Facebook's community standards prohibit users from posting "digitally created" depictions of nudity and sexual activity, "unless the content is posted for educational, humorous, or satirical purposes."

After Cancerfonden's video was taken down, the organization responded with an open letter in which it proposed a different depiction of the cartoon breasts, composed entirely of squares.

"After trying to meet your control for several days without success, we have now come up with a solution that will hopefully make you happy: Two pink squares!" the letter reads. "This can not possibly offend you, or anyone. Now we can continue to spread our important breast school without upsetting you."

Lena Biornstad, communications director for Cancerfonden, tells the AFP that it is "incomprehensible and strange how one can perceive medical information as offensive," adding: "This is information that saves lives."