I had a little bit of a scare recently with my bank's local ATM. About 18 months ago, they started putting stickers on the sides of the card scanners at their ATMs that had the bank's name on the sticker, and right after you swipe your card (and before you input your PIN), the screen asks "Do you see the bank sticker on the side of the card swiper?".
2 weeks ago, I went to my same bank ATM, and the sticker was gone (there was even the adhesive residue there where the sticker used to be), with a different card swiper installed. I was instantly suspicious, and tried swiping my card. I grew even more nervous when I noticed that the card swiper was VERY narrow, and I could barely get my card swiped in the slot (thinking someone put something over the swiper). The first screen didn't ask about the sticker, but instead asked me what language I wanted! Then, the next screen asked me to input my PIN, never asking about the swiper. At that point, I figured it was a legit reader....but I had a few nervous seconds there.