I’ve just watched a “Mr Bean” routine where he just did this; it seens to be a staple for television. Where did this start, why do comedians do it, and what would if you really tried to mess with a Palace guard?
I’ve a feeling if you truly “messed with them,” you could be arrested for harrassment, and I think if they feel they’re being harrassed, they will indeed move.
Keep in mind I’ve no real grasp of laws over there, but I imagine there would be circumstances in which they may move.
'Twould be fun to mock them, though. Perhaps stand in front of them and have a staring contest they aren’t aware of?
Is it true they can’t move at all?
I’ve wondered about this, too.
next time i’m in london, i’m flashing them 
I believe most of the guard posts also have a short patol route that is walked at the guardsman’s discretion. It serves to keep their circulation going since standing still for a couple of hours at a time is tough even for fit soldiers.
If you screw with a guard a little too much I think there’s every chance he’ll come rapidly stepping forwards with a crash of boots, turn and march off on his patrol route. I hear this usually scares the kids off, especially since nobody expects them to move.
Besides, why pick on the guards? I try not to annoy them for the same reason I don’t moon the police snipers - they carry loaded assault weapons.
In America we don’t stand for that type of crap, sir!
Blublblublblub
I just sold an Isuzu I-Mark to the Queen.
It’s roomy enough for a king.
or a queen if that’s all you got
There’s AIR CONDITIONING so her highness won’t sweat!
and a stereo to drown out the cries of the peasants.
Prices start at 7 pounds, 9 ounces
but I traded one to WHAT’S HER NAME for THIS hat!
Joe Isuzu, rattling a Buckhingham Palace Guard