Link: Gizmodo

So, Ive been seeing a few postings in different places over the past couple of days about people seeing these devices in the wild. A card skimmer is a small electronic device placed in line with a card reader (in the case of most ATM machines they are little face plates) that records your credit/debit card’s number [I've linked to the Gizmodo article as they have actual pictures to give a little visualization].

Bottom line, just use a little extra caution when swiping your card. If something is wrong alert the branch manager (in the case of a kiosk there should be number you can call).