It seems like one could make a bluetooth snooper that looks for people who connect to the skimmer? Then you could catch skimmer users when they download the data.
I mean, sparkfun are great, but they're not pentesters. The fact that the police went to them probably means they didn't have the resources to hire a pentesting firm (or do it internally). I'd also guess they don't have the resources to police these crimes either (which would mean a lot of hanging around at gas stations).
This being the case, the criminals have likely either already figured out how to avoid the cameras (or park out of sight). Or the police are not acting on this information because it's not seen as a priority.
...except for the timestamp of the installation event. Or the resources required to brute-force through mountains of footage to find the event.
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.
Every morning just check each pump. Pretty basic stuff and that would mean easy-to-discover skimmers never sit for > 24 hours. You could then assign liability to undetected skimmers after a window of time.