You must leave as few clues as possible. That’s the only rule.

You have to talk to people sometimes; it’s inevitable. There are orders to be given, shipments to be arranged, people to be killed, etc., etc.

You cannot exist in a vacuum, for goodness’ sake.

You need to ring François Loubet? In an absolute emergency? You’ll get a phone with a voice-changer built-in. And, by the way, if it’s not an absolute emergency, you’ll regret ringing very soon.

But most communication is by message or email. High-end criminals are much like millennials in that way.

Everything is encrypted, naturally, but what if the authorities break the code? It happens. A lot of very good criminals are in prison right now because a nerd with a laptop had too much time on their hands. So you must hide as well as you can.

You can hide your IP address — that is very easy. François Loubet’s emails go through a world tour of different locations before being sent. Even a nerd with a laptop would never be able to discover from where they were actually sent.

But everyone’s language leaves a unique signature. A particular use of words, a rhythm, a personality. Someone could read an email,...