They must have caught on in Macau. I was there two years ago and I played some Poker at the Casino Grand Lisboa. I was playing $5/$10 (US equivalent of about $1.50/$3.00) so I had a bunch of $5 and $10 chips. the chip values I believe are in Portugese dollars but I can't remember. Anyway, when I cashed out at the cage, the cashier passed each and every chip under a UV light to look for something. I just thought it was interesting that they checked each and every chip and these were the lowest denomination chips they had.