A few years back I received one of those notes telling me to collect a parcel from the Post Office. When I got there, I was handed a package that contained a hardback book with a kind note inside from a good friend.

It was the first time I realised that my friend had been keeping a diary. And here, under the imprint of a big name in publishing, was the result. “All our yesterdays” as my friend’s note put it. He wasn’t joking. The book contained a record of many of the meetings I had been in over the last few years and what I had said in them.

And if the meetings hadn’t quite taken place yesterday, they hadn’t taken place all that long ago, either. I was lucky. It was a good book and I came out of it well. I didn’t resent it and I still adore my friend. But I was pretty shocked. And so, although the journalist part of me applauds any insight provided into the secret world of the police, there is also a large part of me that sees why they would want to close Nightjack down.

A blog sounds different from a formal diary. But it isn’t really. This is the Crossman diaries, or the Benn diaries, done in real time and online. And these publications, while riveting, do raise questions of the duty the authors had to keep private conversations private.

Yes, Nightjack was anonymous. But this was never likely to last. In politics there is a saying: “Don’t do or say anything you wouldn’t be relaxed about seeing on the front page of the Daily Mail” (a rule many MPs seem to have forgotten). If you publish a blog with the aim of entertaining people and even allow it to go forward for the Orwell Prize, you can’t be altogether surprised if your name gets out.

It may have been entertaining and informative to blog about current cases and police action. But was it ethical? Or loyal to your colleagues? Those, however, are issues for the author and his employers to sort out.

For the rest of us, well, Nightjack was superb. It deserved to win the Orwell Prize , not because it was written by a modern George Orwell, but because it took you inside real life in a way you couldn’t go by yourself. To me, blogs which build a picture of real life are the king of our form.

Daniel Finkelstein writes The Times blog at Comment Central

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