A year ago, my mom gave me her SmarTrip card to use on the DC Metro system. SmarTrip, like GoTo, Oyster, and others is a smart card.
I used it on a recent trip to DC to go from the airport to downtown. I then met my mom for "tea". On my way back to the airport, the card no longer worked. The station agent kindly gave me a get of jail free pass, and I made it to the airport. When I asked SmarTrip what happened, they said the card was cancelled. Having not cancelled it myself, I asked who did this (My speculation was on bots harvesting unregistered cards, registering them, canceling, and transfering balances somewhere.). They said they couldn't tell me, but "ask a relative".
My mom, forgetting she gave me the card a year ago, thought she lost it, so cancelled it that morning, since that was the morning she was going to use Metro to meet me in DC, and wanted to transfer the balance to her new card. Lesson, the card is most likely to be cancelled when it is most needed.
She was kind enough to send me a new card in the mail, which I just registered under my own name.