Umbrella Etiquette

I can understand owning the an umbrella with the diameter of a mini cooper if you live in suburbia and rarely ever walk next to anybody, but for the love of the little baby Jesus, why on earth must you break that thing out on a crowded sidewalk in Manhattan?

And don't give me a dirty look when I duck underneath you. Just because the umbrella broadly covers the area does not therefore make all sidewalk space beneath it your property.

Dick.