the please don't sign was done by an artist in the style of transit authorities signs lol, love subway art. Never been on an nyc subway, but i was on a DC subway once, i thought east los angeles was bad....lol.
I've smiled at strangers in NYC. And they smiled back...maybe they were just showing their fangs. lol Subways are a trip but the tunnels are the best. You can hear concert quality music down there. Great acoustics.
I often have to take the NYC subway system. You see and hear everything imaginable. But I don't smile at anyone. I keep to myself with my headphones on. Lol