For a free press, how far is too far?

Downing Street spin-doctor-in-chief Andy Coulson's ongoing phone-hacking imbroglio is the kind of story that student journalists love. The sense of access to power - wittingly or otherwise - is one that aspiring newshounds crave, and the dark hint of illegality and sleaze gives the saga that extra sheen of intrigue and deceit. It's hardly 'All the President's Men' - indeed, many of the News of the World's much-trumpeted exclusives stretch the definition of 'investigative journalism' to breaking point. But the furore reignited by The New York Times' recent investigation of British tabloid tactics offers a tantalising glimpse into the newsrooms many of us hope to one day work in.

The spotlight shining on the newspaper industry recently may illuminate some fascinating corners, but it also throws into sharp relief many of the cracks in the tabloid press' brash facade. At heart, it's the toe-curling stupidity of it all; the question roaring in the collective imagination is an obvious one - how can you build a story around quotes taken from a private message left in someone's voicemail inbox and expect not to get caught doing it?

Great journalism often finds its roots in criminal acts. The 'Collateral Murder' video which catapulted confidential document emporium Wikileaks into the headlines recently surfaced as a result of an illegal leak by a member of the US military. The popular tendency is to praise or vilify a journalist's actions based on a contextual judgement about the story's legitimacy, but this is invariably a mistake.

To frame this question in relevant, albeit strictly hypothetical terms, consider this fictional scenario: a reporter at The Journal discovers that the Principal of the University of Edinburgh is secretly lobbying the Scottish Parliament in favour of tuition fees. Our hack in the making comes by this knowledge not through careful, methodical journalism but by covertly accessing the Principal's voicemail messages. The paper runs the story, and the Principal finds himself on the receiving end of a furious outcry. The story, and the methods behind it, are widely rationalised as an exposé firmly in the public interest, or at least in the interests of The Journal's readership.

Then imagine the same intrepid journo pulls the same stunt on a student sabbatical officer - at EUSA or NSA, say - and manages to unearth a particularly sordid piece of information about that representative's private life. A series of tawdry revelations about the hapless politician are published, causing great personal embarrassment and leaving the paper prey to an outpouring of damning criticism for its gross invasion of personal privacy.

The only substantive distinction between these two cases is one of context. In one case, phone hacking yields results praised as triumphs of investigative reporting, and the reporter's tactics are treated somewhat forgivingly. In the other, the same methods are decried as muckraking sensationalism. The problem here is that both examples are indefensible. No matter what the outcome, the ends cannot justify the means when we are discussing criminal newsgathering techniques. Breaking the law to prove that someone else did so isn't good journalism but hypocrisy. The mantra must be simple and sacrosanct: responsible journalism means never having to burn the evidence.