A British train operating company has discovered a way to make its trains run on time: blow the whistle. Staff have been issued with ultra-loud and penetrating whistles, which hustle dilatory passengers onto the train in a throwback to the glorious days of steam.
Of course, 'whistleblower' has long since acquired an altogether different meaning. Nowadays they are the heroes - or more likely, heroines - of public life, the people who fearlessly expose wrongdoing in their organisations, putting public good ahead of private gain.
Two years ago, Time magazine put three women whistleblowers - Cynthia Cooper of WorldCom, Coleen Rowley from the FBI and Enron's Sherron Watkins - on the cover as their People of the Year. In the UK, Dr Stephen Bolsin unveiled misconduct in the performing of open-heart surgery on infants - at the Bristol Royal Infirmary - and Dr Andrew Millar from British Biotech publicly (and accurately) disputed his own company's optimism about the prospects of new drug products.
The value of whistleblowing in countless areas of life, from pensions to tobacco, is such that the whistleblowers are now rightly shield-ed by the 1998 Public Interest Disclosure Act from counter-attacks by their employer or erstwhile employer.
But there are dangers here, too. The power of publicity can be harnessed to less noble causes; revenge, for example. The reason why Clare Short's careless talk about bugging at the UN annoyed pretty much everyone was not so much the doubt about the veracity of the reports as the sense that her motivation was spite, not right. The line between courageous public spirit and sour grapes is not always easy to draw.
Similarly, Katharine Gun's recent GCHQ revelations may not have landed her in jail, but they didn't cover her with glory either. The only way to contradict her claims was to unveil sensitive information - and the possibility remains that her outspokenness put lives at risk. But in this case, as in many others, the mission succeeded simply through the coverage it generated. The thing about mud is that it sticks.
Accusations of sexism or racism, leading to high-profile tribunals, are now as much part of life in the Square Mile as currencies or cocaine.
Many - perhaps most - are probably true. But as most are settled out of court, it is impossible to know. Institutions are so anxious to avoid a public relations bloodbath that silence is usually worth a high price.
Of course, serious wrongdoing has to be stopped as soon as humanly possible and whistleblowing is a highly effective brake. But there is a difference between a clear wrong that should be publicised and a mistake, difference of opinion or a minor transgression. Only the dirtiest laundry needs to be washed in public. Even the Millar case is not as clear-cut as it seems at first sight. He was right that the firm was putting a positive gloss on its prospects in its communication with investors, but who doesn't? Again, the line between promoting a positive image and distorting facts is not always easy to draw.
But 'transparency' is all the rage; companies are urged to let it all - good and bad - just hang out. This is a terrible prospect. Imagine if the same rules were suddenly applied to personal relationships. At a dinner party, an innocent request about a couple's wellbeing might get the following answer: 'Well, we haven't had sex for a year, Bob is terrible in bed - a fact that Sandra, his secretary, seems not to mind - and I'm turning to valium and a regular roll in the hay with my personal trainer to keep sane ... So, how are you and Dave?' Opacity has its value too.
And in just the same way that couples need to work some stuff out in the privacy of their own homes, companies have to resolve most of their problems internally - without the help of the media. 'Confidentiality helplines' have the advantage of enabling intimidated people to draw attention to genuinely dangerous or unethical behaviour, but they have the disadvantage of allowing people to stab colleagues in the back.
After all, even if an investigation shows that someone is entirely blameless, the surrounding furore leaves its mark. Think of the countless teachers who have been cleared of sexual wrongdoing: the press run the accusation on the front page, but the clearance appears in a single paragraph on page 34. The same is true for the parents whose children are whisked away by social services on grounds that turn out to be false. Lives can be ruined almost as effectively by false, loud accusations as they can by real ones.
After all, the reasoning goes, there's no smoke without fire.
The trouble is that in a scandal-hungry age, flooded with a media that seems determined not only to find but to lower the common denominator, there are plenty of opportunities to make smoke without a single flame.
None of which is to say that blowing the whistle on wrongdoing is wrong - simply that we have to be careful not to assume automatically that a public claim is more valuable that a private truth.
When we do cry wolf, it is important that a wolf be found.