I haven’t done a security on a train piece for a moment, but I’m in the midst of a fascinating moment. Sat behind me is a Conservative MP – whose name is likely to be known to you – barking out all sorts of stuff into his mobile phone. He’s getting a bit stroppy with someone at the moment, so let me just take a minute to listen in…

…. ah, back now!

Given that this gentleman is happy to talk in a loud, snooty voice, it’s fair to say that, by my estimation, the entire carriage and a good deal of passengers in the next now knows his mobile number that he’s just given out, the name of the man at the Daily Express he’s trying to talk to, his movements for the next few days and what a rude sort of a man he is. He’s not so much talking down to people, as digging holes for them underground to sit in, so he can further establish his superiority. He seems to like scrawling on his piece of paper, though. A shrink would have a field day with it.

It’s a continual theme that the biggest compromise to any well thought-through security system is a human being rather than a machine. In this case, the only reason this particular Member of Parliament is likely to find at least two phone numbers compromised is because he’s made such a song and dance on the phone, and bleated them out at volume.

The moral of the story? Be careful what you talk about in public, and what you show people on a screen.

And don’t sit near me on a train.