Facebook will learn from a mistake it made by deleting a historic Vietnam war photo of a naked girl fleeing a napalm attack, said Sheryl Sandberg, the company's chief operating officer. The photograph was removed from several accounts on Friday, including that of the Norwegian prime minister, Erna Solberg, on the grounds that it violated Facebook's restrictions on nudity. It was reinstated after Solberg accused Facebook of censorship and of editing history, The Guardian reports. From the article:"These are difficult decisions and we don't always get it right," Sandberg wrote in a letter to the prime minister, obtained by Reuters on Monday under Norway's freedom of information rules. "Even with clear standards, screening millions of posts on a case-by-case basis every week is challenging," Sandberg wrote. "Nonetheless, we intend to do better. We are committed to listening to our community and evolving. Thank you for helping us get this right," she wrote. She said the letter was a sign of "how seriously we take this matter and how we are handling it."