The first rule of having an adult conversation is to know what you’re talking about. FBI director James Comey, who wants an 'adult conversation’ about encryption, clearly does not. In that lies a big business opportunity for non-US software firms.

Addressing a conference last month, Comey harped on about a pet subject: that of criminals 'going dark’ and the need for law enforcement to be able to access encrypted data and communications. He wants US companies to implement backdoors into their encryption systems. In fact, he likes to call it a 'front door’, presumably thinking of SWAT teams ramming them down in pursuit of people to terrorise.