If people are given the right to complete privacy, some will abuse it. It is not just terrorists and paedophiles who will use encrypted communications to work obvious evil. Anonymity releases all kinds of small-minded malice and cruelty even in normal people. This has been claimed by philosophers for centuries – Adam Smith wrote that it is the fear of becoming “the proper object of the contempt and indignation of mankind” that enforces our moral codes. Take that away, he argued, and there is little to prevent us acting for reasons of pure self-gratification. Thirty years’ experience of social networks on the internet has proved that the Scottish philosopher was right. The Twitter mob, the skulking trolls and other hate figures of our time are evidence enough of that. So there is a moral case for removing some degree of privacy on the internet. It will not do simply to assume that freedom for users is an unmixed good.

Yet, mixed though it is, it is still a good. Human political authorities are not God and are not perfectly good and disinterested. They cannot be trusted with omniscience, or even with too much knowledge and power. Since one of the motives for our good behaviour is the fear of “the contempt and indignation of mankind” if our dark acts and urges were discovered, enormous power belongs to anyone who learns our secrets. That power will certainly be abused. The instinctive suspicion and fear of anyone who knows too much about us is the root of hostility to Facebook, Google and the other targeted-advertising businesses. Every web browser now has a “privacy mode” to allow people to do things – however legal – that they wouldn’t want others to find in their browsing history. To have secrets to keep is part of being an autonomous individual. A balance needs to be struck. The widespread availability of reliably encrypted and so completely private methods of communication, such as WhatsApp, Signal and Telegram, actually strengthens democracy.

Arguing otherwise is the kind of illiterate technological determinism which too often derails discussions of freedom and privacy on the internet. The enemies of democracy and of honesty in public life depend far more on anonymity than on privacy. What is concealed by privacy-enhancing technologies is not the content of the messages but their purpose and origin. This encryption depends on mathematical principles that are accessible to anyone. The technology itself is, in this limited sense, democratic. That is why governments have been unable to limit its use to areas where they might approve of it, such as the banking system. That would still be undesirable even if it were possible, but since it isn’t possible, the only route for authoritarian governments is to ban the use of certain applications altogether.

This is what first Russia and now – apparently – Iran have done with Telegram, a popular instant messaging app which is widely (not universally) considered entirely secure. China has been much more assiduous and effective in blocking, banning and monitoring private channels of communication. Analysts assume that everything can be eavesdropped on and watched by the state. The Chinese model is one that tempts governments everywhere, and it can’t be resisted entirely by high-minded appeals to principle. As often happens, things that are confused and muddy in principle are perfectly simple in practice. It is the simple, almost apolitical recognition that privacy is one of the things that we need to be fully human that is the strongest defence of private, encrypted communications online.