I find your statement to be pretty offensive to so called "children". You are implying that they are completely helpless and have no ability to make decisions with consequences. In my book, if they can figure out how to use the internet, tor encryption, bitcoin, order something through SR, all without it being detected by anyone who cares to stop them, they are certainly mature enough to comprehend the consequences. Please consider that you are turning kids into bubble boy (if you've seen that movie).
Kids are often offended by restrictions imposed on them by parents and other adults. Kids also often think they are indestructible and know everything. Maturity, in many ways, is the awareness of your own mortality, and ignorance. Plenty of "smart" people, young and old, remain very immature. Especially when it comes to drugs.