So, New Yorkers AREN'T hostile beasts?
Say it ain't so.
The Readers Digest did a secret shopper test for politeness.
A couple of facts they seem to have missed:
1. People are paid to hold the door open for you in this city. They are called "doormen" and in fact they are unionized.
2. "Thank you" is New York dialect for "hurry up".
3. When we help you pick up papers on the street we're picking your pocket.
and you'll notice, they didn't test the subway!
(Thanks to the "other MS" for the link)