An amusing subset of the subway demographic:
The Oh Shit I'm in Brooklyn Tourist
Regular commuters see this all the time. A group of mostly domestic tourists will hop on a downtown train figuring they all go to Ground Zero, Century 21, etc, get confused, miss their stop, head under the East River, pull out their subway maps and realize they're in Brooklyn. Eyes get wide. Panic sets in. Hopefully then a reassuring NYer will tell them just to go to the other side of the Fulton, Borough Hall, Court St., platform to return to civilization.