Travel etiquette

[Milz]

(subtitled: Cultural Question from an American)

My friend was reading some travel magazine article regarding 
etiquette tips for certain countries. The article stated that in some 
parts of England it is considered rude to ask a person from which 
part of England he comes. Is there a reason why it is rude (ie. is it 
considered to be too personal a thing to ask a person?) In the US, 
it's not uncommon to ask someone "what part of the country are you 
from?" as it serves as a conversation starter.

Milz