There are lots of practical and privacy issues with actually enforcing age restrictions. Many governments are currently thinking of trying to do this with porn,

There are lots of practical and privacy issues with actually enforcing age restrictions. Many governments are currently thinking of trying to do this with porn, and no one has provided a reasonable way to do so yet. Simply adding a disclaimer that you must be 18+, or asking the user to enter their birthday is not going to prevent problems like this from occurring, it's just a flimsy attempt to shift the blame.