They're only doing their job but for some reason tourists seem to think they can try and make fun of the Queen's Guard.
Well you can't.
Otherwise they'll point a very large gun in your face and shout at you.
Fair enough really.
This unfortunate gent was on the receiving end of this after trying to place his hand on a Queen's Guard while he was parading.
The guard brings his gun and very pointy bayonet dround and screams: "Step back from the Queen's Guard".
The Ministry of Defence has said the reaction was appropriate and no further action will be take.