Nobody can predict where the fallout from the News of the World phone-hacking scandal will end up, because the old assumptions have crumbled, while nobody knows what the rules of the game are going to be.
News International has been for three decades the most aggressive and confident corporation in Britain when it comes to asserting its own interests. This week, it adopted a classic defensive strategy, using a standard toolkit of tricks, from denial to distraction, confident of its ability to see off anti-Murdoch MPs and a tweeting mob. It failed badly - underestimating how much the reaction would come not just from politicians and tweeters, who the corporation tried to dismiss as politically motivated, but also from parents, from advertisers and investors.
There was genuine shock at a series of acts which were unimaginable even for those used to thinking pretty much the worst of the rougher end of the newspaper trade.
There has always been some cognititive dissonance between the robust common sense "voice of the people" positioning of some red-top tabloids, and the ruthless and often cynical professional culture which underpins their operations.
That has now been stretched beyond breaking point.
For a newspaper which posed as the strident champion of victims to break the law so as to spy on the families of murdered schoolchildren, terrorist victims and dead soldiers has simply destroyed, perhaps beyond all repair, what the News of the World told its own readers that it stood for.
And the backlash is new territory for an organisation so used to aggressively demanding accountability from everybody else, while jealously protecting itself from scrutiny. It has managed its relationships on the assumption that it was usually able to strike fear into its interlocutors - even when it came to Parliamentary scrutiny or the forces of law and order. But the old arrogance has not gone away. There have been remarkable briefings to journalists. The BBC's politicial editor told the nation on the ten o'clock news that Murdoch would close ranks around Rebekah Wade "because this Is family" - striking language when the issue has become one of criminal conspiracy.
To see why the scandal matters, reflect on how this all so nearly stayed under wraps. News International has retreated slowly, always conceding only what had become indefensible, always claiming to have fessed up, cooperated fully and investigated rigorously, before being shocked by the next set of revelations about its own activities. They had allies across the press, an unwillingness to ask questions reflecting guilty consciences as to what a wider inquiry will no doubt uncover. Without the dogged persistence of The Guardian and Channel Four, and the New York Times' magazine investigation, they could have carried on with business as usual at Wapping, operating outside the law with apparent impunity.
The police's unwillingness to investigate, even when looking starkly at criminal activity, could prove the biggest scandal of all in an inquiry.
Perhaps it was the final hubristic triumph of the media age that spin doctors are not just the most persuasive voices in Downing Street, but that the head of media relations for the police apparently got to veto the idea of prosecuting powerful friends in the press.
The culture of impunity in red top newsrooms, the self-regulation of the PCC are rightly on trial.
Yet this is a dangerous moment too. The old journalistic instinct to resist all scrutiny or change as threatening a free press will prove too defensive for this moment - but there are real threats and dangers of get this wrong.
We have a press too trammelled from free inquiry by our restrictive libel laws, yet which has brought its own valuable freedoms into jeapordy through a culture among too many of believing itself to be entirely outside the law. Those senior journalists like John Lloyd and Ian Hargreaves who have joined external critics to advocate a stronger journalistic ethic, more rigorous scrutiny and self-criticism inside the profession, have tended to be dismissed and marginalised as lofty and unworldly quasi-academic figures. But they were right.
We now need to move from reaction to a much broader civic and journalistic quest for and advocacy of a new media ethic.
The uncovering of this affair, and what it has uncovered, has shown journalism at its dogged best and its unprincipled worst.
"I'm all for the free press; it's the newspapers I can't stand", as one of Tom Stoppard's characters says in Night and Day.
The urgent task for defenders of a free press now is to win confidence that the newspapers can change.