That's nothing new. This bad boy...

Is one of NYPD's most effective investigative tools. It's NYC's transit pass the most ubiquitous possession among NY-ers. And that mag stripe records every turnstile, system-wide, at which it's swiped. So when the cops pick up a suspect who's past whereabouts they're interested in, they just pop his/her MetroCard into a reader and BOOM! Every move over the lifetime of the card is right there. My last card expired 6 years ago almost to the day, but I couldn't bring myself to throw it away, so it's been tacked to my bulletin board ever since I left Gotham. But that mag stripe still carries my travel history for my last few months in Manhattan and Brooklyn.
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