The sophisticated encryption software that now comes as standard with many electronic gadgets is, in many ways, just another instrument of modern life. Like air travel, international banking and mobile telephones, it contributes to all kinds of productive human endeavour — and also presents new security risks. But there is a difference. Its rapid and organic growth left little scope for regulatory control and balance.

The police are sometimes characterised as despotic agents of digital repression. That is wrong. I have never believed that encryption should be banned; it is a fundamental part of how the internet works. But its utility and effectiveness, like that of the internet as a whole, also creates significant criminal opportunity by masking identity and hiding communication.

Other innovations that have multiplied the freedoms of modern life were the product of democratic deliberation, and incorporated security by design. When telephones were introduced, a set of balanced legal instruments gave police the power to intercept them. Financial institutions have become more complex, but they are compelled to operate strong anti-money laundering controls.