In various forms, this has circulated the 'Net for several years. IIRC it has been posted at XMarks at least once in the past with similar discussion following. BTW it was not penned by John Cleese (see Snopes and, according to them, Cleese's own website).

Things to remember:

Humor is a very personal matter, difficult to convey in the ether.

This is an international forum with members from each of the many nations mentioned.

How would you react to an "ugly American" version of this material?