One of the casinos announced they were going to include RFID chips in all there Gaming chips. They will know exactly what you bet is when you put it on the table.
I had heard about that, but as far as I know, it hasn't been implemented yet. From the way the dealers skirt the subject when it is brought up, there must be some way the casino's detect counterfeit chips now. If not, the industry would be flooded with fake $25 chips.
I know that they try to 'balance' cash against chips or tokens, but that is almost impossible, as people walk out with them, or are wandering around in the casino with them not in play.