By Torin Douglas
Media correspondent, BBC News
The words jail and journalist do not often go together - and when they do it is usually a big story.
The idea of an editor or correspondent behind bars is an emotive one - particularly to other journalists - often embodying powerful concepts such as freedom of speech.
Some journalists face jail for reasons widely seen as honourable - refusing to betray a source, for example, which brings risks of contempt of court.
But Clive Goodman, the royal editor of the News of the World, has been jailed for entirely different reasons - he admitted hacking into hundreds of mobile phone voice messages.
Had he been trying to expose matters of genuine public interest, this too might have been seen as an honourable pursuit... or at least justifiable. Instead it was described by a judge as "a grave, inexcusable and illegal invasion of privacy".
Goodman was simply looking for stories - any stories - about Prince William, Prince Harry and the Prince of Wales.
With a private investigator, he made over 600 calls to the voicemail boxes of three of their aides - Helen Asprey, Jamie Lowther-Pinkerton and Paddy Harverson.
He and his newspaper have since issued public and unreserved apologies.
What Goodman found was scarcely earth-shattering and in no way a matter of public interest. In fact, it was hardly of interest to the public.
One story which made Prince William suspect his staff's phones were being tapped was about a knee injury which led him to postpone a mountain rescue course. Only three people knew of his doctor's appointment.
A second report revealed that the ITN journalist Tom Bradby had lent the prince some broadcasting equipment. The story appeared before they had been due to meet, again raising suspicions.
Goodman was jailed despite the current political row about overcrowded prisons, which has seen more dangerous offenders go free.
And it marks a new low point in the relationship between the royals and the media, at a time when the press is also under fire over its coverage of Prince William's girlfriend, Kate Middleton.
As a possible royal bride and potential future queen, Kate is increasingly being compared with Diana, Princess of Wales - and increasingly facing the same harassment and intrusion into her private life.
On her 25th birthday, with rumours rife of an imminent engagement, she faced a media scrum outside her front door, with hardly any security to protect her against the cameras.
She was visibly shocked - as the TV cameras showed - when the paparazzi pursued her down the street.
Soon Rupert Murdoch was ordering his newspapers - including the Sun and News of the World - not to publish paparazzi photos of the prince's girlfriend.
Others have not been willing to make that commitment - and indeed it is by no means clear what constitutes a paparazzi photo.
The BBC News website still carries a snatched photo of Kate Middleton shopping, which it says came from a "reputable" picture agency.
The appetite for royal news and pictures is huge and the market highly lucrative, in many parts of the world. The mobile phones case shows just how far journalists will go in pursuit of a story.
'Tip of iceberg'
And this is the tip of an iceberg, according to the privacy watchdog, the Information Commissioner.
He has published a report showing that over 300 journalists, working for some of the best-known tabloid and broadsheet newspapers, have paid for personal information such as details of phone calls or bank accounts.
But the interception of royal phone messages is not new. In an earlier age of mobile phone technology, both Prince Charles and Diana were severely embarrassed by phone calls which found their way into the tabloid press.
One infamous recording, which came to be known as "Camillagate", was a tape of an intimate late-night phone conversation in 1989 between the prince and the then Mrs Parker-Bowles.
The prince was heard telling Camilla he wanted to be with her, and making highly intimate comments.
Another was the so-called Squidgygate or Dianagate tape, dating from the same year, of a conversation between the princess and a close friend, James Gilbey. Both tapes emerged only later, after the rifts in the marriage became public.
After that, the Press Complaints Commission hardened its code.
It now says that: "The press must not seek to obtain or publish material acquired by using hidden cameras or clandestine listening devices; or by intercepting private or mobile telephone calls, messages or emails; or by the unauthorised removal of documents or photographs."Yet that still seems a rule "more observed in the breach than in the observance."