When French magazine "Closer" published photos of Kate Middleton topless on vacation in France, the royal family issued a statement calling the incident "reminiscent of the worst excesses of the press and paparazzi during the life of Diana, Princess of Wales." They've also decided to sue the magazine, according to the AP.
That's a big contrast to how they approached the photos of Prince Harry partying naked in Las Vegas, which also surfaced recently. In that case, taking the matter to court was never discussed. Typically, the royal family has a policy against suing the media, and the British media largely cooperates with respecting their privacy to a certain degree. The royal family requested that the photos of Prince Harry not be published, and the media mostly complied. Only one paper, "The Sun," published the photos, and when they did, the royal family issued a statement saying, "We have no further comment to make either on the publication of the photographs or on the story itself concerning Prince Harry's private holiday in Las Vegas," according to the BBC. "We have made our views on Prince Harry's privacy known. Newspapers regulate themselves, so the publication of the photographs is ultimately a decision for editors to make," they added.