It’s a rule of thumb — two rules, actually — that if you consistently support free speech you’ll end up defending someone you personally find objectionable, and that very few free speech defenders are consistent. It’s easy to stand up for speech you agree with, but rather more difficult to go out of your way to defend speech to which you object. And a lot of times free speech involves hard cases of speech on the border between merely offensive and actually harmful, meaning you end up making subjective judgments that X is merely objectionable, but X+1 would harm someone, and therefore doesn’t deserve defending. Staying consistent in your subjective judgments is difficult, unless you’re some kind of free speech absolutist, in which case you don’t care about what anyone says, even if it leads to people dying. There aren’t too many of those around, thankfully.

So … two cheers for Liberal senator Cory Bernardi for being consistent this week, because there is a ferocious assault on free speech underway in the very centre of public life at the moment and the 18C crowd — the old white men who are affronted that their right to be bigots is notionally infringed by the Racial Discrimination Act — are nearly all silent. Only Bernardi has spoken up.

The assault is the Australian Federal Police investigation to identify the whistleblower who embarrassed NBN Co by revealing how badly behind schedule and over budget its Turnbull-inspired switch to cheaper, poorer non-broadband technology was going. Police raided a politician and his staff, trying to secure their communications with whistleblowers and journalists, including press gallery journalists.

Along the way, an NBN Co employee who accompanied AFP officers in their raid handed material over to NBN Co despite it being subject to a claim of parliamentary privilege, and NBN Co chair Ziggy Switkowski deliberately and knowingly breached caretaker conventions to defend the raids on Labor during the election campaign. And these are raids that are, on the face of it, simply illegal, given NBN Co is not a public service agency of the kind that means its staff are public servants bound by APS secrecy provisions. It’s noteworthy that both the AFP and NBN Co have ducked and weaved on that exact issue, rather than saying outright that their legal position is sound.

[Ziggy is dust: NBN Co head must resign]

This week, the raids extended inside Parliament House as AFP officers entered and, with the assistance of Senate staff, went looking for emails between ALP staff and journalists. That seemed to bestir Bernardi into seeking his own advice about the privilege claim Labor had lodged over the material the AFP wanted to seize, rather than relying on the government, which has sought to paint Labor as engaging in some outrageous attack on the integrity of the AFP. “I’ve always been of the view that parliamentary privilege is inviolable,” Bernardi said. Nick Xenophon, who has a consistent history of support for whistleblowers and whistleblower protection, has already flagged support for Labor’s claim.

What Xenophon knows from experience, probably better than most of his major party Senate colleagues, is that whistleblowers need to be able to come to politicians every bit as much as they need to be able to approach journalists. At the moment, however, what few protections there are for journalists do not extend to politicians.

When Malcolm Turnbull and George Brandis were imposing the mass surveillance “data retention” scheme in 2015, there was a last-minute revolt by media companies over access to journalists’ data, which led to the insertion of a “journalist information warrant” in the legislation requiring special procedures for any effort to obtain information about a journalist’s source. There is no similar protection for politicians — no “politician information warrant” that would require the AFP to prove to the satisfaction of an issuing authority, with the advice of a public interest advocate, that obtaining the data of politicians or their staff was justified.

Had similar requirements been in place this week, the AFP would have been required to obtain a special warrant to obtain material exchanged between ALP staff and journalists. And the matter would have been referred to the Joint Committee on Intelligence and Security, which could pursue it if it were so minded to do so.

No one is suggesting the ALP haven’t used the NBN documents to embarrass the Coalition, or that Stephen Conroy is a model of consistency when it comes to transparency on the NBN, but whistleblowers are a crucial means or non-government politicians to do their job of holding governments to account.

[What you need to know about NBN raids — and why it could help Labor]

There’s been little outrage from the media about this, despite the targeting of journalists — though as the government’s “special intelligence operation” amendments in 2014 and the mass surveillance law demonstrate, the mainstream media, especially Fairfax and News Corp, are slow to speak out in defence of their own rights — if they ever do.

Also silent have been the 18C crowd. Andrew Bolt did speak out back during the election campaign about the raid on Labor, wondering why people shouldn’t know about the NBN debacle, although he didn’t mention the matter this week. But beyond Bernardi, nothing — not from IPA Senator James Paterson, or from David “angry white male” Leyonhjelm, or Malcolm Roberts, the diminutive foe of “international bankers”, or from the opinion pages of The Australian, which has been campaigning enthusiastically on 18C. Perhaps the latter would have been stirred to its usual “old man yells at cloud” level of high dudgeon if it had been Coalition senators and their staff being pursued by the AFP instead.

Maybe it says something about the priorities of the 18Cers that they’re more angry about a nebulous and ineffectual restraint on their right to demonise minorities than a very real and practical demonstration of free speech being undermined by a government war against whistleblowers and journalists — and the politicians who support them.

The message being sent to potential whistleblowers by the AFP investigation is, deliberately, chilling: there’s no safe place for you to go — politician or journalist, neither can protect you, and they’ll go after their digital records to try to identify you. Strange that advocates of free speech are so silent on such a flagrant assault.