Are we supposed to believe no one noticed this email for 18 months?

Which of us has not sent an embarrassing email to the wrong person? Those of us who have struggled with Excel know just how easy it is to clip and send the wrong part of the data set.

- Bernard Gray

And yet, and yet... The MoD data breach is not like this, not at all.

For a start, unlike most organisations, the MoD runs two computer systems. One called Official/Sensitive, which is a bog-standard system, and one called Secret, which is very different. About 10% of MoD traffic is on Secret, and is much more restrictive in what you can do and who can see it.

Secret is used for communicating about current military action, security concerns, and almost anything to do with the special Forces. It isn’t on the MoD system used for holiday requests and parking spaces.

So how do the full details of nearly 19,000 Afghans end up exposed, along with information on over 100 of the UK Special Forces and spies? It’s at the least very odd. If it had been on the Secret system, then our unfortunate sender couldn't have emailed it to the outside world.

Then there is the MoD habit of copying everyone in. Apparently, there were a few people outside the ministry who were sent this workbook. But the MoD always covers itself by copying in at least half a dozen insiders.