system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:How come hotel key cards get erased by being near cell phones, but credit cards don't?
gpt
I actually asked something similar a while back and was given a fair answer. What it boils down to is the strength of the equipment used to magnetize the cards. A stronger device magnetizing the card means you'd need a stronger magnet to wipe it.