How difficult can this be to understand? Stand by for a mandatory group training exercise. See your department manager for a training charge number:
OK, everybody repeat after me, "No spare uninstalled batteries in checked baggage"!
"No batteries in baggies, no loose batteries, no batteries in a sock with your loose change and paper clips"!
"Nada, none, zip, No way, Jose"!
If you want to carry spare batteries, they MUST be in your carry-on baggage. It would be very smart to put them in a plastic bag (the TSA inspectors will be impressed and may even overlook the cattle prod). Most of the Canon batteries that I know of also have a plastic shield to protect the terminals -- you did keep it didn't you? It has a purpose -- that is why Canon provided it with the battery. The new rule is not a stupid regulation -- it is there to protect the majority of us from the few people who don't get it.
Well, OK, I will admit that there are some dumb regulations. How the heck are we supposed to whip business partners, clients, customers, and hangers-on into shape without the necessary tools at our disposal, i.e.: cattle prods, hand grenades, and gasoline.