When it comes to the rich, the famous and the infamous, much can be written about them from what they leave behind. Not only the personal effects, letters, diaries, journals and books they still have in their possession, but those they have passed on, especially letters to other people. And if that is the case, we have absolutely no right to those things we may have written and then sent on to another person.

So if that is the case, it is entirely up to the person on the receiving end who ultimately decides what to do with them. In the first instance, Princess Margaret received letters from Princess Diana, and decided to dispose of them - given we will never know what was in them, we have no idea why and there the speculation may be worse than the original content. As for Nietzsche, again we have no control over what happens to our documents and records once we have passed away. Unless you have an executor willing to carry out your last wish that is.

So what is the moral of the story? Well, be wary of what you write, it may come back to bite you. But the more interesting aspect doesn't relate to paper documents anymore, rather the electronic ones we don't think twice about creating. Is an electronic document truly gone or merely hidden away in the computer memory waiting for the family historian to find them?

The burning question of Diana's letters - Telegraph

But did the Princess have the right to destroy historic material? I suspect she did. The Royal family may be public property – but they are still a family. Their personal letters belong to them, not to the nation. They are not Public Records.

But, the most chilling example of archives being wilfully destroyed, however, relates to Friedrich Nietzsche. After his death, his anti-Semitic sister Elisabeth burnt everything with which she did not agree, and posthumously published in a single volume, called The Will To Power, those fragments with which she did