Last year, against my better judgement at the time, I used my CC at Bubba Chinos on West Colfax (warning sign #1) for lunch. The guy swiped it through a reader on an iPhone (warning sign #2) and at 11:00 pm that night I got a text alert from US Bank wondering if I was trying to buy$250 worth of fuel in Commerce City. Turned out there were a couple of small "feeler" purchases earlier in the evening as well to make sure the card data was valid.