Disc-shaped UFO following a plane over China - December 2012

An unnamed passenger has passed on a photograph of what appears to be a UFO stalking a plane. The picture is taken from the window of a commercial passenger jet.
The disc-shaped object was captured on a flight from Hong Kong to southwest China's Kunming City last week .
A friend of the anonymous passenger, Larry Siu, says the picture was passed on to him and was taken by a friend, who he refused to name.
No details of the exact day or which flight the passengers were on has come to light, yet...