As there's only a few pump manufacturer's which means only a few master keys, it would make sense for the fuel station, to check each pump before opening up every day, if not open 24hr, and if they wanted to be more secure, to check all pump's every few hour's, then run back through any CCTV should a device be found. Yes it's more work, but unless there's penalties attached for fuel station's to keep their equipment secure, just like medical centre's need to keep their equipment secure, so repeat prescription's are not modified or other historical record's interfered with which could lead medical expert's down the wrong course of action which could be life threatening, (think removing penicillin warning's) then what hope do you have?

All consumer's can do, is use fuel station's which have good CCTV fitted, and if really unsure, to pay inside.

The companies that manufacturer these card's do so for many businesses, they are a high value target, one's like Oberthur, & Gemalto to name just a few and have global franchises with many. These guy's are under pressure to get card's out to customers for various entities as quickly as possible, so you'll find many card's are similar except in print design, and stamping. As a result hacking these card's due to being globally standard, make's life easier for hacker's as well, so I wouldnt be surprised to see similar technique's like card skimming being used in other outlets that accepted payment's especially where staff are not involved like some McDonald's outlets or vending machine's.

It seem's if you have intelligence, you can live freely or vastly reduced provided you can remain anonymous when old school CCTV and other methods are used to identify you.