Various countries have tried to implement this – or hint at introducing it, for example Canada and UK recently – but there has always been friction in the whole process. It seems to me that proliferation of digital legal ID, especially during the pandemic, has oiled the processed and such a proposal will be easier to implement. Perhaps not even in the way it is described here (akin to checkpoint analogy) but rather as a whole system process (proof once and we will decide what you access, perhaps at the device set up point, using biometric ID linked to government issued legal ID). In the end, therefore, the adult content (in this case), will be filtered even before you get there if you are a minor. An anchoring background process, not necessarily a checkpoint.