It's ID cards, so it's going to have a chip or sensor that isn't powered: it'll simply grab current geolocation on swipe. It also wouldn't be usable off campus

It's ID cards, so it's going to have a chip or sensor that isn't powered: it'll simply grab current geolocation on swipe. It also wouldn't be usable off campus for anything the school wasn't providing. Also since it's ID cards: when swiped the machine would be communicating back to a central server to get balance (and thus tracking) OR they're pulling it off of the card's state at the machines directly, then writing to the card where it was used and then pulling all that data when they recharge the cards. 3rd potential option being reading each machine that interacted with the cards and collating but I see that as less likely, given the wording of the article. Any way you look at it: it's something credit card companies already do.