Extending the analogy would be a pretty weird but plausible thing - you show your ID to buy "internet credits" then go home and use them however you want. But those credits probably have an ID or known endpoint that will be tied to your ID/credit card.
Until someone finds a clever and credible way to anonymize "internet credit", we could just outlaw any internet-connected devices in possession or in use by a minor. To extend the analogy, just like a bottle of whiskey. For the safety of the minors, of course.
