There is a psychology experiment on the effect of a uniform on obedience. What it was is that psychologists put up made up uniform on someone, a uniform that doesn't correspond to any actual office or government, or anything. The person in the uniform goes out on the street and then somebody's passing by and the person in the uniform says:
- Look, this person is overparked on this parking meter. Give him a nickel.
(...)
And then you put somebody who doesn't have a uniform, who does the same script. The result is that people are more likely to obey the person with a uniform.

Michael Huemer "The Psychology of Authority"