The Metropolitan Police's attempt to force The Guardian to reveal confidential sources in relation to the phone hacking scandal was an unprecedented and worrying move. Protection of sources is a central tenet of journalism and is covered both by the reporter's moral code and, more importantly, by law.
In 1989 a trainee reporter on a trade magazine was given information about the financial difficulties of an engineering company. The firm obtained an injunction preventing the magazine from publishing the story and requiring the reporter, Bill Goodwin, to disclose his source.
Mr Goodwin refused and was fined £5,000. But seven years later the European Court of Human Rights ruled in his favour, finding that protection of sources is "an essential means of enabling the press to perform its important function of public watchdog in a democratic society." Several other precedents have been set in the years since the Goodwin case, all of which have come to a similar conclusion.
This week we saw a rare consensus across the national print media. The Daily Telegraph, The Times, The Independent, The Financial Times, The Daily Mirror and even The Daily Mail all ran leader columns condemning the Met's plan, prompting the force into an embarrassing climbdown. It could be argued that The Guardian went a little overboard in celebration - an arty front page picture of Amelia Hill doing her best "look at me" face - but there's no doubt this was an important moment.
The growing accessibility and immediacy of opinion sites means there is no shortage of journalists, bloggers, commentators and 'media experts' queuing up to have their say. My personal tuppence-worth comes from my experience as a reporter on a local newspaper. We may not be dealing with the Official Secrets Act or issues of national security, but freedom of expression and access to information is something we battle to uphold almost every day.
There is a fundamental conflict that takes place in every newsroom around the world between those who want information - the journalists - and those who want to withhold it - the official channels, most commonly press officers. There is a complex game being played, much of it unspoken, involving quotes, queries, requests, rebuffals and the dreaded deadlines. The PR machine is in place to make organisations look good and to stop them looking bad.
The stories of council cock-ups, police corruption and health trust disasters that continually make the headlines are just the tip of the iceberg. These are the stories that got through the barrier and made it out, often leading to resignations, apologies and policy changes.
And how did they manage to slip through the net? Oh yes. Sources. Reporters work for years making friends in high places in the hope that one day they will come through with a scoop. Most of them don't, of course. There remains a distrust of the media that means people will keep quiet more often than spill the beans despite being certain of an injustice or scandal. But every so often it works.
Earlier this year a document was posted through our office door. It was the result of a "staff temperature check" carried out by the local council. It showed that council workers are stressed, unhappy with their jobs and losing confidence in their bosses. We never found out who leaked the letter, but the resulting article led a member of the council's senior management team to privately admit it was a "bloody good piece of journalism."
A similar story about a school's plans to leave the site where it has been for 70 years came from a reporter's close relationship with a well-placed source who we ensured could remain anonymous.
And an ongoing investigation is currently in progress which, if all goes to plan, could result in an extraordinary story. This particular source has come forward as a result of hard work by our editorial team to gain their trust. These are genuine examples of exposing what goes on behind closed doors, behind the all-powerful PR machine that wants the world to see its masters in the best possible light.
Reporting is not just about writing the story - first you have to find out what it is. Take away our sources and you take away our means to probe, to investigate, to be the eyes and ears of the public. And you take away the rights of people to tell us what they know without fear of reprisal.