Hmm are you sure? I thought they were just using hole cams still. Little cameras built into the rail or into the table that players just showed their hands to while playing.
Yep, that's the old tables problem is it's up to the player to show their hands and some either don't care or don't want to reveal their startegy ... I think they even have RFID chips, it makes the game much more televisable
rfid/nfc is popular at the moment simply because it's cheaper; no table to cut up or glass/cameras to put everywhere.
as a poker player i've always been queezy about the idea that my hand could be read remotely in theory -- but I don't play those kind of tables anyway.
https://en.wikipedia.org/wiki/Hole_cam