conversation: User (terusama): "Really sorry if this is the wrong sub. Please direct me to the right place if it is because I would like this question answered.\n\nI was buying breakfast just now at an airport when my card got declined. Confused, I checked my online statement and I have 300 dollars in charges that I didn't recognize. They date back about three days ago. I googled the information provided near the charge (like how it'll say CVS MIAMI 0000xxxx or whatever) and they're charges being made at gas stations. How are they using my card like that if I have it here with me? I called immediately and had my account blocked so it's not an issue anymore but I'm just curious as to how this was done.\n\nedit: Thanks so much to everyone for the explanations, especially /u/sir_not_sir . Also thanks to everyone sharing stories. Hopefully getting the money back will be painless. I genuinely thought that credit cards were somehow more "secure" than things like hotel cards so that getting a card writer for credit cards was not possible.\n\nIf for whatever reason my ignorance is quite personally frustrating for you, perhaps you may enjoy reading [this.](https://xkcd.com/1053/)"
  Self: "At some point, you used the card at a location with a card skimmer.\n\nYour information was duplicated and sold to someone with a card writer. That card is now a clone of the card in your possession and linked to your account.\n\nOne of the many reasons that credit cards are getting upgraded to chip and pin technology."
  User (terusama): "I didn't even know card writers existed. That seems silly but now I actually understand skimmers. Thanks.\n\nedit: more meant to say, I didn't know credit card writers (that regular people could get) existed. Didn't think they were the same as other mag strip cards."
  Aznguy001 (Aznguy001): "There are even devices that just copy credit cards, without you needing to Scan it"
  