Commenting on the growing obsession with secrecy within defence and other areas of government, he made the point there were "official secrets" and then there were "officials' secrets".

The former were legitimate issues of national security which should be protected.

The latter were matters which had the potential to embarrass ministers, public servants and officials.

"Defence has been getting more and more secretive, or less transparent, year by year, for the last decade or so," he said.

"Things like project schedules and budgets... it's hard to see how they are of any national security importance."

Mr Davies's handy rule of thumb is a good one to apply to the reports that resulted in the recent raids on the home of Canberra-based News Limited journalist Annika Smethurst and the ABC offices in Ultimo.

Ms Smethurst reported on proposals that would have allowed security agencies to spy on any Australian without the need to apply for a warrant.

The ABC's Afghan Files brought to light serious allegations that Australian special forces troops in Afghanistan had been involved in unlawful killings and other possible war crimes.

While both of these reports proved highly embarrassing to a legion of politicians, political apparatchiks and various public service mandarins, it is hard to see how they compromised national security in any shape or form.

By exposing some very serious allegations of government overreach on the one hand, and of troops behaving badly in a war zone in the other, the media was actually doing the nation a favour.

The reaction to the Smethurst story was such that it should be a cold day in hell before our security czars float a similar proposal again.

The exposure of the Afghanistan allegations helped to ensure the matters were investigated with due rigour and diligence rather than being swept under the carpet.

They included claims the bodies of enemy fighters had been mutilated and that men, women and children had been the victims of extrajudicial killings.

These are very serious matters.

Australians have a right to know what our troops serving overseas are doing in our name.

The raids were in the news again this week.

An unlikely alliance, made up of Nine Entertainment (the owner of The Canberra Times) chief executive Hugh Marks, News Corp Australia executive chairman Michael Miller, and ABC managing director David Anderson, appeared at the National Press Club to call for legal changes to protect the public's right to know.

The three media organisations are seeking the right to contest search warrants on journalists and news organisations before they are issued and adequate protections for public sector whistleblowers.

They also want a limit on what documents can be classified as secret and exemptions for journalists from recently enacted national security laws.

"We have got to make the case that freedom of the press is also personal because, if you don't have it, you've lost something," Mr Marks said.

"You [have] lost the right to be informed and you have lost the ability around which to make great decisions."