A mobile application can reportedly "track" flights of both Queen Elizabeth and Prince William's helicopters - and terrorists can very well download the app for just £2.99.
According to The Independent, "Flightradar24" can potentially bring in "a major security risk" to both royals since it provides detailed flight information of both copters.
Express UK added that the app offers the "altitude, speed, GPS coordinates and route of the flight" of the royal helicopter as well as the air ambulance that the Duke of Cambridge currently pilots.
The same news site reportedly used the app earlier this week to track the monarch's Sikorsky S76C helicopter. It took off somewhere near the royal family's summer home in Sandringham and landed in London sometime later.
The experiment also noted that the vehicle had been flying at just a few hundred meters from the ground "well in range of even a crude surface-to-air missile" at a speed of 150 mph.
Meanwhile, Mail On Sunday was able to receive notifications about the second-in-line to the throne's East Anglian Air Ambulance every time it took off for an emergency call.
Military air vehicles are reportedly concealed from the app but the same cannot be said for air emergency services and, apparently, for royal flights as well.
This could definitely bring Queen Elizabeth and Prince William, as well as other important figures who use non-military helicopters, in range for potential attacks.
"This would give me cause for concern and solutions need to be found by those in charge of the Prince's security," Dai Davies, the former head of the Met's Royalty Protection Squad, reportedly told the Mail. "You always have to be aware of the advance of technology - which this illustrates - and the ability of these terrorist groups to think outside the box. You always, always have to be one step ahead."
Buckingham Palace and the Metropolitan police as well as The Bond Aviation group (which operates the East Anglian Air Ambulance) have not commented about the possible threat to Queen Elizabeth and Prince William's life from the "Flightradar24" app.