From the moment the Sun newspaper story broke, the Twittersphere was seething with comment. But the story - newly discovered film showing the Queen as a young child, and her mother, raising their right arms in imitation of a Nazi salute - divided the tweeters like few others.
One school of thought claimed that the public has every right to see a piece of evidence which may reveal the real attitudes of Britain's first family. The other - and seemingly larger - school declared that this was private family footage, its source unclear, and that the future Queen, a young child at the time, couldn't have been aware of the politics, anyway.
So, which school is right? Both are, of course. Or neither, maybe.
The Queen was indeed only seven or so - and dutifully doing what she was urged to; as this Queen has always done, through her maturity. As far as the blame game goes, the Queen is out of it: and rightly. Her mother, on the other hand, was a grown up - but even the Sun were careful not to cast aspersions on the 'Queen Mum', stressing her stalwart record during World War II every step of the way.
And the Queen Mother has a get-out clause - two of them, maybe. Firstly, we don't know the context of a gesture made on silent film. Many people in his early days were mocking 'Herr Hitler' - children goose stepping along the streets, with a finger held across their upper lip where a moustache would be.
Many felt and continued to feel that mockery was a good weapon - Charlie Chaplin among them, famously. He later said he regretted making his 1940 release The Great Dictator - that had he known the actual horrors of the concentration camps 'I could not have made fun of the homicidal insanity of the Nazis.' Point is that at the end of the Thirties when he was filming, there was a limit to what anyone did know - to say nothing of five years earlier, when the royal family made their home movie.
There's a different sort of interest in the filmed action of the third player in the salute drama - the future Edward VIII. (Excluding, that is, an infant Princess Margaret; Princess Elizabeth's dog; and the person behind the camera, who may well have been the Queen's father, the future George VI.) Edward and Wallis Simpson have been accused of active, sustained, and even traitorous Nazi sympathies.
In his 1951 memoir, A King's Story, the Duke of Windsor as he then was wrote that Hitler 'struck me as a somewhat ridiculous figure, with his theatrical posturings and his bombastic pretensions'. (Never mind that Hitler sent an inscribed gold box as a wedding gift when he married Wallis.) That his own political attitudes in the 1930s were guided wholly by a desire to preserve European peace... It's not convincing, frankly.
So, yes, there is a genuine historical interest in footage of Edward encouraging his niece to give the salute this early in the decade, when he was still expected to reign over the country. But I'm not sure it tells us much we didn't know before - it's elsewhere the real lesson of this story lies.
The fact is that in the early years of Hitler's ascendancy, he had many well-wishers among the upper echelons of English society, where he was seen as offering a welcome alternative to the communist nightmare. Many 'fellow travellers', as they were described to me when I was doing a BBC interview yesterday. It was and is, moreover, difficult to distinguish sympathy for Hitler as such, from a mere desire for peace. It's surely a sliding scale, just how far it was worth going down the path of appeasement, to prevent Europe's falling back into the bloodbath of World War, from which it had emerged only recently.
So the point about the actual 'fellow travellers' must be how long they stayed with Hitler on the road; and how much they understood about the real purpose of their journey. The point about those who, perhaps unthinkingly, just raised a right arm (as did the English football team, playing a friendly in Berlin in 1938) - well, that's more fundamental, actually. And that's what's important about this new footage.
It's not about the Queen, or about privacy. It's not even about whether the Queen Mother had, and retained into later life, prejudices we'd find unacceptable today. As a woman of her time and class - and not the most intellectual among them - she will have done, almost certainly.
There is a different reason why this footage did need to see the light of day. It isn't about the royals - or only in so far as, once again, they're seen as an exemplar of our national identity.
The point is just how far a rot can spread - the rot of failing, early enough, to see a global threat, a moral outrage, and to take it seriously. And that (apply it where you will) is surely a vital lesson from history.