London, England (CNN) -- In the days after Diana, Princess of Wales, died in a Paris car crash in 1997, the public mood turned against the paparazzi, the army of photographers whose relentless pursuit of her satisfied an intense demand for celebrity pictures.
The backlash helped give rise to a new era in relations between Buckingham Palace and Britain's press proprietors, who agreed firmer guidelines governing the activities of their photographers, particularly when it came to Diana's sons: Princes William and Harry.
But what levels of intrusion will confront William and his newly-betrothed fiancee Kate Middleton as they step firmly into the public eye in the run-up to their wedding next April? Will the royal bride face media interest beyond her control?
Industry insiders say some photographers will be tempted to cash in -- although fear of legal recriminations will keep most at bay.
However, unpleasant memories of Diana's ordeal could be revived if big-paying overseas magazines seek potential exclusives, such as the first pregnancy bump; or the marriage falters and photographers declare open season.
"It is a lot more ferocious now, believe me," public relations expert Max Clifford told CNN, comparing today's press photographers to the paparazzi that hounded Diana. "If you thought it was bad then, just watch."
"As long as they are the popular and fairytale marriage, then the press are going to behave themselves because it will backfire on them."
But, Clifford added, at the first sign of marital trouble, Middleton will be "walking into a media minefield."
For all the dire warnings, veteran royal photographer Arthur Edwards (once known as Diana's favorite) insists things have changed.
"This isn't the aggressive 80s when Diana was around," said Edwards, who works for the tabloid Sun newspaper and who hopes to shoot William and Kate's wedding. "This is much more restrained."
So far, photographs of the royal couple have been few and far between, with only one organized photo call just hours after the engagement was announced. The scarcity of images is seen as a reflection of the royal family's unease following Diana's death.
Diana was being followed by paparazzi on motorcycles when the car she and lover Dodi Fayed were traveling in crashed, killing them both. The circumstances of her death are seen by many as a tragic consequence of her unprecedented public exposure.
Perhaps wary of this, Diana's sons have jealously guarded their privacy, bowing out of the limelight at key times during their upbringing. During his time at St. Andrew's University in Scotland, William appeared in barely a handful of press photos.
Since entering royal circles, Middleton has also tried to stay away from prying lenses.
In the hours after the engagement was announced, William's press secretary sent an email to journalists and photographers covering the royal beat in London, reminding them "that the Middleton family remain private individuals."
It also asked them to remind their picture desks of industry body rules about "the use of photographs that may have been taken following harassment or a breach of privacy."
Middleton -- who was memorably mobbed by photographers outside her home on her 25th birthday in 2007 -- has already successfully sued for damages and an apology after photo agency Rex Features syndicated images of her playing tennis during a private vacation. Rex said it had been unaware of an invasion of privacy at the time it ran the photographs.
"Kate has used the courts before to restrain intrusion and newspaper editors in Britain don't use those intrusive pictures any more," said Edwards. He told CNN that although he expects Buckingham Palace to increase the number of photo calls as the couple heads unavoidably into public life, there will still be limited legitimate opportunities for candid shots.
"If she was maybe shopping in the West End [of central London] and someone caught her with her bags of shopping, then fine. But not intrusive into her family home or on holiday somewhere or in a private place -- no, that won't happen.
"Obviously people want more, people want exclusives, but as long as it's not intrusive or dangerous by chasing her in cars or on motorcycles."
Despite a huge worldwide demand for images of the couple, photo editors are also now wary of using intrusive images, which they say can end up costing more than they earn.
"The value of unauthorized photographs of William and Kate has never been lower because the Middletons and everybody else are very aggressive legally," said Sam Barcroft, head of international photo agency Barcroft Media, based in London.
"There's vast demand for any pictures of the prince and princess-to-be, but there are very few photographers who are willing to try and shoot unauthorized photos because they realize the Middletons' lawyers will be down on them like a sack of potatoes."
Barcroft said his agency had already been approached by foreign clients for "sets of pictures of them in candid situations" near their new home in Anglesey, north Wales, but added that "it's not something we'll be pursuing."
"There may be some people probably foreign-based photographers who decide to take a trip over to Anglesey to see if they can take a picture of Kate popping out to the local shop but I doubt there will be any British photographers doing it."
According to the photo editor of a leading British celebrity gossip magazine the big money will be paid out for the first images purporting to show a pregnant Middleton.
"The picture that will be worth something will be her with a bump," she told CNN on condition of anonymity. "That's what everyone will be looking for, her getting pregnant."
She said that even though "the paparazzi has changed massively since the death of Princess Diana," ongoing sensitivity over this issue would inform the magazine's decisions over whether to use such images.
According to Ken Wharfe, one of Diana's former bodyguards, one legacy of the death of the Princess of Wales is that her son will be prepared for the press scrutiny ahead, and will try to protect his bride-to-be.
He said: "The advice [Diana] gave to William was the best ever: 'Look, you may not like it, but you'll have to get up and take it.' And I'm sure William has passed on that advice to Kate."