Biometric identification technology is indeed very effective, the system detects it in just seconds, I haven't heard of anyone who can fool the system. Too many gambling sites and minors will definitely find other solutions so they can gamble, the most to be considered is their connection and the role of parents who should monitor whither they access website, restrictions that must be increased.
I can attest that its also effective since we are using it too in our company every time there is a need for fast verification. However, even if that technology is very advanced and can eventually pinpoint if you are faking your identity or not, that does not guarantee that its never be scammed by brilliant minds of minors. Technology should also know that. So for me, its really hard to control the minors these days not to gamble, unless if the parents should take