http://www.bbc.com/news/world-europe-42157129
tl;dr someone discovered that 13 cards in a deck had been treated with medicinal iodine-25, which is radioactive, allowing someone to detect marked cards using a worn piece of hardware.
the only conceivable way this works is if somehow, they have some sort of directional detection embedded in eyeglasses i guess? so they look at the opponents hands and it alerts if they have marked cards maybe? is that even possible?
otherwise what, it silently tells you if your cards are marked, which doesnt strike me as a huge advantage play...