I've always thought this would be a great use of the blockchain. If you want to party with dangerous drugs you take your pharmacy card to the pharmacists and ge

I've always thought this would be a great use of the blockchain. If you want to party with dangerous drugs you take your pharmacy card to the pharmacists and get a recreational prescription. This gets written to the blockchain. Next time you do it they see your full history. If your usage is showing patterns of abuse then they can refuse your request and sign you up for legally binding treatment program.