The royal family is facing a row with YouTube after a video it says breaches the Cambridge family's privacy was viewed by tens of thousands of people despite attempts to block it.
The video, which was viewed more than 20,000 times on Monday, shows the Duke of Cambridge confronting a photographer after he was filmed on a bike ride with his family near Sandringham, Norfolk.
William, 40, is seen remonstrating with a man videoing him, while his wife and three children are off-camera nearby.
In the video, William is seen calling someone, presumed to be security, on his mobile phone and saying to the man: "If you want to have this altercation we can have this altercation."
The man claims he wasn't following the family to which a furious William replies: "Yes you are, you are stalking around here looking for our children."
William then references an incident on Saturday where the man also followed the family while on a bike ride and lashes out when the man denies following them.
"You are outrageous, you are disgusting, you really are. How dare you behave like that."
Kensington Palace has responded by arguing it was a breach of the family's privacy. The short video was uploaded four days ago, more than a year after the incident occurred.
It underlines the significant challenges facing the royal family in the online era, where rules followed by the traditional media do not apply.
Kensington Palace says the film is a breach of privacy, with the duke on a private bike ride with his wife and three children, who were present but blurred out in the video.
It is understood staff are seeking the removal of the video. On Monday, the three-minute-long video was still available on YouTube, with a version circulating on TikTok as well.
The traditional British print media does not publish photographs or videos of the royal family in private circumstances, being particularly sensitive to images of Prince George, Princess Charlotte and Prince Louis.
The duke, who watched his mother's experience with the paparazzi as a schoolboy, has spent years finessing an arrangement in which he authorises a small number of photographs of the children each year in recognition of their future public roles, while insisting on their total privacy the rest of the time.
But images of the children are regularly posted on social media, and sold to European publications working under different laws and press watchdogs.
The duke has previously been highly critical of social media firms and their approach to fake news, privacy issues and cyber-bullying, accusing them of failing to take the issues seriously.
The latest video was filmed in January 2021 near the Cambridges' Anmer Hall home where the duke, duchess and their three children were riding their bikes along a country lane.
It shows the duke confronting a photographer who claimed to have been in the area on public roads only looking for the Saturday Sandringham shoot.
It is understood that Kensington Palace has asked for it to be removed from the platforms, in line with their usual policy about privacy.
Staff have previously been successful in appealing for unauthorised photographs of the children to be taken down.
The duke has previously warned of the dangers of social media networks and what he saw as the disinclination of their executives to deal with a range of problems which affected users.
"I am very concerned though that on every challenge they face – fake news, extremism, polarisation, hate speech, trolling, mental health, privacy and bullying – our tech leaders seem to be on the back foot," he said in 2018.
"Their self-image is so grounded in their positive power for good that they seem unable to engage in constructive discussion about the social problems that they are creating."
A spokesman for YouTube has not yet commented.