KEY POINTS:
Whatever one might think about the revelations in Nicky Hager's book, The Hollow Men, one thing is certain. Email exchanges between politicians in this country and their fellow travellers will never be the same.
Hager writes that the former National Party leader was "an almost obsessive email writer" who spent hours each day writing and replying.
No wonder there was such a rich vein of material for Hager to mine. Don Brash was the unknowing author of his own misfortune.
Hager left out personal information about Brash's private life, because, he writes, "people have an overriding right to privacy in these matters".
Not so other emails and papers Hager says were leaked by National Party members whose "primary motivation was a wish for more principled and democratic behaviour in the National Party".
There was a "strong public interest" in leaking that information: "The intrusion is permissible because of the scale of dishonesty and unprincipled behaviour it reveals."
The former National MP, Marilyn Waring, who writes the foreword to The Hollow Men, comes to the same conclusion despite concern about the "extraordinary breaches of privacy".
Waring observes that while Hager's work met "high academic standards", he would never have received ethics approval from a New Zealand university "because of the extraordinary access he has had to private and personal communications".
Waring is shocked by the extent of the leaks, and impressed by the detail. But it is hardly surprising Brash and co were caught in the digital equivalent of Candid Camera.
Email might give us the illusion of intimate conversation, but its ease and convenience is a trap. We tend to forget that our mutterings don't disappear harmlessly into the ether like an old-fashioned phone call.
But it's not only politicians and public figures whose lives are laid bare by the digital age. And not just the not-quite-with-it old guys like Brash who haven't woken up to the privacy threats posed by the digital age.
Never before has so much been known about so many. As Google's CEO has said: "We are moving to a Google that knows more about you." He didn't mean that in a threatening way, but we should be afraid nonetheless.
So is privacy dead? Is it even possible in the digital age? Is the tech-savvy generation really less concerned with privacy than their elders, given the amount of personal sharing and blogging that goes on these days?
I consulted my 12-year-old, who was born the same year the first commercially available web browser was launched. He is a true child of the internet, beyond tech-savvy. Technology is his first language.
Like others of his generation, he's comfortable with putting himself and his personal information out there. He has pages on Bebo and MySpace, on which are detailed his likes and dislikes, his favourite games and pastimes, and, for example, the fact that he doesn't want to have children.
He's posted a video he made himself, and once, before we made him take them down, silly photographs of himself and his brother, dressed as terrorists, which they'd taken with a mobile phone. A little warped, yes, but it seemed funny to them at the time.
Yet, despite his willingness to share himself with perfect strangers, he's not quite as thrilled with me having access to his password. It's an invasion of his privacy, he declares.
Which proves one thing: just because kids are technologically fluent doesn't mean they understand the privacy implications of their digital activities. What, years from now, will come back to bite my son in the bum? At 12, he hasn't thought that far ahead.
But it's not surprising, says Australian privacy advocate Roger Clarke, that most of us still haven't got our heads around digital privacy given the internet as we know it is only in its first decade.
We've yet to fully understand the invasiveness of web-bugs, Plaxo, Google and Google's free webmail service, Gmail. I'm a recent convert to the latter, but as Clarke points out, it now holds an astounding amount of personal information about users like me - including who I talk to, what we talk about, the sites I visit and copies of my computer files. Apparently, I'd exchanged "some" of my privacy for a tool Google persuaded me was useful.
Perhaps this is an evil plot on the part of the companies, but some seem almost as blithely unaware of the privacy implications as the people who use them. In September, for example, Facebook, a social networking site, was forced to apologise after 700,000 users signed an online petition demanding the company discontinue notifying users of all their contacts' activities, including profile changes from "in a relationship" to "single".
Still, most of us seem to have a lowered expectation of privacy in the digital age. We don't seem to think twice about employers routinely combing through our emails and web usage - even though this is fiercely opposed by some privacy advocates, who see it as an intrusion too far - on a par with secret video surveillance and eavesdropping on private phone calls, neither of which we'd tolerate.
Clarke argues privacy is a fundamental human right, and technological surveillance produces a chilling effect on people's behaviour, which is bad for the economy, the individual and society in general.
He says people need privacy in order to feel free enough to experiment and innovate - innovators being, by definition, deviant - and that surveillance chills political speech and undermines democracy.
I agree with most of that - I write much more tempered emails now. But I think most people weary of manipulation by political strategists and spinmeisters would argue the opposite of surveillance isn't conducive to democracy either.
Maybe the idea of an all-seeing digital eye has its uses. In the apparent absence of any moral imperative, the threat of public scrutiny may be as effective a motivator of honourable behaviour as any.