PARIS • When an advertisement featuring a famous artwork was reworked - the woman's breasts were now covered with a banner saying "censored by Facebook" - the social media giant did not take offence and ban it from the site.
However, it had taken down the advertisement when it depicted French artist Eugene Delacroix's famous work, Liberty Leading The People, as it was rendered - with a bare-breasted woman.
On Sunday, however, Facebook admitted to making a mistake for banning the original advertisement.
The 19th-century masterpiece was featured in an online campaign for a play showing in Paris, when it ran into trouble on the social networking site, the play's director Jocelyn Fiorina said.
"A quarter of an hour after the advertisement was launched, it was blocked, with the company telling us we cannot show nudity," he added.
He then posted the revised advertisement with the banner.
Delacroix's subject, who brandishes a French flag in the painting, is not just any woman - she is Marianne, a national symbol of the French Republic.
Fiorina had already tried twice before in June without success to use the painting, which was once featured on a franc bank note, in publicity for the play.
On Facebook's change of heart, its manager Elodie Larcis in Paris said in a statement: "The work, Liberty Leading The People, rightly has its place on Facebook... We have immediately informed the user that his sponsored publicity is henceforth approved."
"In order to protect the integrity of our service, we verify millions of publicity images each week and, sometimes, we make mistakes," she added.
With more than one billion users, Facebook is often challenged over its authority over content on its site.
Last Thursday, a Paris court threw out a case brought by a French teacher who wanted to sue the company over his claims that his page had been censored when he posted a nude painting by Gustave Courbet.
The latter is credited with leading the Realism movement in 19th-century French painting.
The court, however, added that Facebook had made "a mistake" in not specifying to the user the reasons for its move.