This was on the PATH (subway between NY and NJ) but I've seen it before on the regular NJ Transit Trains and the NYC subway.
I've also seen someone light up a cigarette on the subway - not on the platform, literally in the subway car as we were going along. But he was talkign to himself, rocking back and forth and wearing a black garbage bag as a shirt, so no one bothered him - we all just got up and moved at the next stop.....