I received this picture today. The original filename suggested that it was taken at Notting Hill Gate station. I have no idea whether it was really on display at a Tube station or not; in any case, I think it’s safe to say that it’s not an official statement from London Underground!

Notice to all passengers. Please do not run on the platforms or concourses. Especially if you are carrying a rucksack, wearing a big coat, or look a bit foreign. This notice is for your own safety. Thank you