John Levine wrote:
In the NY area, ATMs tend to be located in an inside lobby, with a
latch on the door you can open by swiping any ATM or credit card.

Not just an ATM or credit card -- anything with a magstripe.
Including a Metrocard, which has a totally different encoding scheme.

It's clear the door lock devices aren't reading your complete card
number, since you only have to put your card in a fraction of an inch
before the door unlocks.

Jimmy