Color is a new photo-sharing app that tags photos you take with your iPhone, according to where they were taken. The photos are then uploaded to Color's servers, so you can see pictures other people have taken at the same event -- whether you know them or not.
This anonymity is a source of concern for the police. "It has been brought to our attention that it may be possible to post inappropriate, insensitive or even treasonous images of the otherwise happy occasion using this app," said a Met Police spokesman.
"It's strictly forbidden to use this app in the environs of Westminster Abbey and Buckingham Palace on the day of the royal wedding. Police operatives will be monitoring the app and anyone caught uploading unauthorised images will be arrested under the Prevention of Terrorism Act."
The wedding, which will take place on 29 April, is sure to command massive attention on the world's social networks and photo-sharing sites. Google Maps has already added a 3D tour of the royal wedding procession route. But, while the royal family and authorities are keen to encourage people to tweet and Facebook their friends with observations and photos of the event, they take a dim view of more subversive uses of new technology.
When pressed as to exactly what the possible security implications of the app could be, the spokesman declined to elaborate, but flatly denied the ban was to prevent Prince Harry publishing photos of his crown jewels.
Update: This story was published on 1 April, which may alert you to its not being real. We only mention it because some, ahem, trustworthy news organisations have taken it as fact.