There's a little-known paragraph in the Universal Declaration of Human Rights that reads, "No one shall be subject to arbitrary interference with his privacy."
It sits within the declaration - which all states must agree to uphold to join the United Nations - surrounded by other much better known and loved rights like: innocent until proven guilty, freedom of speech, and bans on slavery.
Which may seem surprising, because the declaration was drawn up in the aftermath of World War II, in which those other rights had been trampled almost to extinction.
Until you consider that at the time, the ability to breach privacy on a mass scale by having neighbours informing on neighbours was the exclusive domain of totalitarian governments.
Back at the time that democratic countries like Britain and New Zealand declared war on the fascist powers, common sayings like "a man's house is his castle" and "I don't agree with what you say but I'll defend your right to say it" summed up well the mood that everyone should be free from arbitrary interference by governments. This was something they knew would disappear should the war be lost.
Recently, revelations of systematic mass surveillance by the governments of the very countries that fought so hard to establish this right have been constantly in the news.
News of New Zealand's mass spying on people in the Pacific is just the latest instalment. But there's been little real political fallout.
Which leads to the obvious question: is this a right that we care enough about to keep?
Most of us willingly gave away some privacy when we first started posting our lives on Facebook. So really, why be upset that our governments are doing the same thing, especially to keep us safe?
If there is a debate, it's mostly been the democratic and ethical one: maybe this would have been all right if we'd been told about it and been able to consider the practice when we voted.
So is this just a breach of trust, or is it also a breach of a more fundamental right?
The usual answer involves a scale. At one end we have privacy and at the other security: any increase in one inevitably leads to a decrease of the other. Privacy or security - simply make up your mind which you care most about.
But this dialogue misses three very important points.
The first is around the extent to which this privacy for security trade-off really exists. No one is seriously arguing that there isn't a need for targeted surveillance, to do so would be naive. But the frequent historical lesson is that where states move beyond targeted and into mass surveillance, their people are actually not more secure but less secure. Especially where there are no effective controls on what information government agents can scoop up - and few such controls have been in evidence lately.
Second, we need to face the reality that even in democracies, governments are not always entirely benign. It's not that long ago that Prime Minister Robert Muldoon was accused of using SIS surveillance powers against his political enemies. While data storage is cheap and information sticks around, governments change over time and New Zealand's wafer-thin constitutional protections leave us all open to such abuses in future.
Third, there is now a large amount of research on the importance of privacy to personality and creativity. Humans are social creatures, and the threat that anything we say or do could one day be held against us is a recipe for a bland world in which we always have conformity in the back of our minds - few of us are brave enough to risk being voted off the island.
It's simply no longer possible to live off the grid. Every credit card purchase, every webpage viewed, every phone call or email made, even phone locations are all logged. We can't turn back the tide on that technology, but it's reasonable to demand that our governments don't scoop that up and store it without a specific reason.
This may be the century where that little-known right to privacy becomes one of the most important ones. We owe a debt of gratitude to those who fought to establish that right, and we are right to question any government that takes it away.
• Grant Bayldon is executive director of Amnesty International in New Zealand.