The Guardian's editor, Alan Rusbridger, thanked 'tweeters' for their support
When is a secret not a secret? When it's on Twitter.
An injunction served on the Guardian and at least one other national newspaper was meant to stop the papers reporting that the MP Paul Farrelly had tabled a Parliamentary question about the oil traders Trafigura and its solicitors Carter-Ruck. And it succeeded - up to a point.
In a front-page story, the Guardian said it was prevented from identifying the MP who had asked the question, what the question was, which minister might answer it, or where the question was to be found.
In a twist the paper described as "Kafka-esque", it was also banned from telling its readers why it had been banned from doing so.
In one sense, the injunction was effective. In most of the mainstream media this morning, you would have found no mention of who or what was involved.
No injunction was served on the BBC, but ever since the Spycatcher case in the 1980s news organisations which knowingly breach an injunction served on others are in contempt of court, so the corporation too felt bound by the Guardian injunction.
But the lawyers in this case clearly reckoned without the "blogosphere". In the anarchic, anything-goes world of the internet, where free speech is a frequently-heard rallying cry, injunctions banning publication of anything are unpopular. This one seems to have acted like a red rag to a bull.
The social networking site Twitter was soon awash with posts deploring a threat to media freedom and the reporting of Parliament.
Stephen Fry, celebrity tweeter, called it "this barbaric assault on free speech", and the very information Trafigura and its lawyers were anxious to keep secret was being freely bandied about.
Guido Fawkes's political blog and the website of at least one mainstream publication, The Spectator, apparently chose to ignore the injunction entirely.
A Google search for Trafigura in mid-morning threw up a dozen online articles on the subject.
The digital marketing company Econsultancy - on its own website - observed all the activity on Twitter, saying: "This tidal wave of tweets makes for particularly bad PR, given the banning order against the newspaper.
"It's a bit like an artist achieving a Radio 1 ban, which can result in chart success. What you seek to suppress only generates further interest."
Imposing injunctions on news organisations has never been a foolproof way of stopping information from leaking out. But in the old days, when the principal means of transmission was word of mouth, only a favoured few ever got to hear of it.
The digital revolution has changed all that. Anyone with a PC or a laptop or an iPhone or a Blackberry, or any other digitally-enabled device, can now discover what all the fuss is about.
On this occasion the injunction seems to have been utterly counterproductive. The Guardian obtained a High Court hearing to challenge the injunction this afternoon. But at lunchtime Carter-Ruck bowed to the inevitable, and the Guardian's website was soon running full details.
The first news, of course, came from the Guardian's editor, Alan Rusbridger, via Twitter. "Thanks to Twitter/all tweeters for fantastic support over past 16 hours!" he wrote.
And the Liberal Democrat leader Nick Clegg tweeted: "Really pleased Guardian ban has been lifted. This is a victory for freedom of speech and online activism".
And Stephen Fry's reaction? "Can it be true? Carter-Ruck caves in! Hurrah! Trafigura will deny it had anything to do with Twitter, but we know don't we? We know! Yay!!!"