I was hanging around the gates of this place and a trio of fairly burly guys seemed to be keeping a close eye on me. They walked out of the gates in my direction and I backed off towards the road. After a few minutes I decided to approach any problem they might have had head-on and went and said hello to the two men who were still there. It turned out that they were all smiles so I asked if I could take their photograph.
As I raised my camera the third man, the largest of the three, who was in a guard's hut, jumped out of the window of the hut and ran towards us. It was quite athletic - he didn't bother with the door and approached at speed. I feared some sort of intervention but he ran straight between the two other men and struck a pose for the camera with a huge grin on his face. He was in a rush simply because he didn't want to be left out.
Try the same thing in London and see what happens...