I have read that there is a gadget that thieves can use to read the information on your passport and credit cards even while those items are securely on your person. Well, it would seem that I fell victim to that nasty technology.
I always take three credit cards with me when I travel. Two of them I use frequently, but the third one is simply a backup in case of emergency. I didn't even realize that the third, rarely used, card was going to expire at the end of this month. When I returned from my recent trip to Mexico, my replacement card was there in the mail at home. It wasn't until today that I got around to calling to activate the new card. It was then that I discovered that my credit card had been blocked. I talked to a service representative, and she explained that there had been some suspicious activity on the card. She removed those charges and told me that she would send me a new card immediately.
During my entire time in Mexico I had never used that credit card. In fact, I didn't even have it on me; it was tucked safely away along with my passport in the apartment. The fraudulent charges (there were three of them; all through Doha, Qatar) were made on the day that I flew home. The only possible explanation is that some crook scanned my wallet with one of those devices while I was in the airport... either in Mexico City, or, more likely, Newark, New Jersey.
I double checked my other two cards, and there was no problem. I will, however, be checking them more frequently than usual for a while, just to be sure.
The pouch in which I carry my passport is supposed to block scanners. I was just checking out some websites, and they also make wallets that will block those devices. The problem is, I like the wallet I use when traveling. It is a biker wallet with a chain that attaches to my belt. I feel that it gives me more protection from pickpockets (although I still tuck my wallet in my front pants pocket when I'm on the subway or crowded buses). I noticed that they also make small sleeves in which you can place your cards. I'm going to order a few of those as a safeguard.