I suspect – hope – many have heard of ATM scammers, people who try to get information about your card while you are withdrawing cash from an ATM. I will usually look at a machine to see if it looks like someone has tampered with it and I always use my other hand to cover the one entering the PIN. Perhaps that’s silly, but it’s not much of an inconvenience and it’s routine for me now. But as far as I know, I have never encountered an actual ATM skimmer, thankfully.
A security expert happened upon one during his travels recently and captured it on video. In addition to reading his account of it, I highly recommend a careful look at this image from another observer who breaks down very carefully how some components of the ATM (most importantly the section next to where you insert the card) was different from the adjacent ATM that did not have a skimmer. That is likely where the camera resided. In addition to the skimmer, there is usually a camera nearby that captures your motions entering the PIN (if I am understanding this correctly, but do correct me if I am wrong), which is why I tend to cover my hand (and have noticed that now some machines supply some coverage themselves). Snopes has pictures of another version, an older model.
I found the video interesting as I find actual examples of such things helpful thus this public service announcement. Hopefully no one here has related experiences, but if you do, please share.