Yet even small papers and TV stations are producing stories that transform their communities.

I was at a conference with about 1200 reporters and editors who swapped ideas on how to scrutinise powerful institutions and people. There were local examples: the TV journalist who unveiled a county official's lies about his qualifications and his habit of cyber-stalking women; the newspaper that revealed thousands of methadone-related deaths, details of which the state government had withheld from a regulator. Investigative teams uncovered larger-scale scandals, too: the US-wide practice of radiologists cheating on board exams; the killing of illegal migrants on the Egyptian border so as to sell their organs.

Forty years after The Washington Post's Watergate coverage began the tradition of investigative reporting, journalists are among the US's most important watchdogs. So valued is their work that philanthropists and universities have stepped in to fund public-interest journalism at a time the industry is contracting. American society wants, and pays for, the fourth estate because it believes its work is crucial.

So I was naturally very excited to be learning from Americans new ways I could put my trade to good use. Until I realised a sad truth: most of the US news investigations I examined could never take place here, because Australian laws and attitudes would stymie them.

We have inherited from Westminster and Whitehall a comparatively secretive system of government; one that discloses far less information about its activities than do other Western nations.

This is usually explained away as respect for privacy. Indeed, the reflexive response I often receive to freedom of information requests is that government documents cannot be disclosed as they contain ''personal'' or ''commercial-in-confidence'' material. Yet when challenged, agencies regularly admit they have no right to suppress the information.

This Australian reluctance to share public documents goes well beyond FOI law. For example, the Australian Electoral Commission stores, on its electoral rolls, each citizen's full name and address. It does not publish these rolls online ''for privacy reasons''. Yet, at the same time, it allows anyone who walks into one of the commission's offices to view them.

Our courts are similar. They will typically publish their judgements on their websites, but not the other documents that were part of a case, again citing privacy concerns. Yet anyone who walks into a court's registry can access most of the documents held by that court (for a small fee). In the same way, most hearings are open to whoever turns up. Why it's somehow ''OK'' to allow privacy to be breached in person, but not online, remains a mystery.

Across much of northern Europe, governments publish every citizen's income-tax return. The vast majority of taxpayers accept that this is not a breach of privacy, because they see paying tax as a public duty. This disclosure also makes it much harder to evade tax and easier to reveal those who try.

In the US, many jurisdictions publish registers of everyone who holds a licence, whether to run a particular type of business or pilot a certain class of vehicle. American FOI law also allows citizens far greater access to documents created by government agencies than does Australian law (not even the CIA is exempt). The cyber-stalking county official I referred to earlier was only uncovered after a journalist gained access, through FOI law, to the internet logs on the official's work computer. Those logs linked the official to a website that hosted stolen photos of naked women. In contrast, if an Australian journalist asked to see a public servant's internet logs, the request would be dismissed as a gross invasion of privacy.

Americans proudly (some would say blindly) resist the ''intrusion'' of government in everyday life. They may take this distrust a little too far, but it's created a comparatively open government and a strong watchdog culture among US media. We went down the British path. Perhaps it's time we asked what this is costing us, and what we're trying to hide.

Markus Mannheim edits The Public Sector Informant