Tonight we received a call from our bank. There had been two withdrawals on my credit card that lookes suspicious. One was in Denmark and one was in Canada. Only small amounts. They were obviously done by someone who had stolen the card identity, since I still have my card. The bank had noticed that this problem very often stemmed from Spain. The pattern was familiar to them. The only time we ever used the card on a "slide" terminal was at Alicante Airport. We do have quite good control on this card, since it is a spare one. In Norway the card readers are mostly using the chip, so there are very little evidence that it happened here. The transactions were few as well.
Please note that this is a warning only, I have no proof of where it actually happened. But if it indeed happened at Alicante Airport it was at Norwegian desk, TaxFree shop or the cafeteria at the arrivals area. We will be very careful next time..