Oo! This is a good chance to give out my only little piece of hacker-type info:
Those ATM door-opener scanners work with *any* card with a magnetic strip. It makes sense since they need to work with other bank’s cards and it’s not worth making a call back to a server that actually checks the info on the strip before allowing entry (ever notice how quickly the door unlocks?).

I’ve used everything from my school ID card to a “club card” for the local burrito place (Qdoba) to open those doors. My guess is they’re just there to keep homeless people out. :(