Re: Why is age verification an invasion of privacy ?
> The valid credit card seems a good way
Really? You'd trust any obscure website owner with your credit card details?
As for being efficient, do you really think your children are too dumb to copy the numbers on it, and henceforth be able to enter any website they want? They usually live in the same house as their parents, it would be trivial for them to eventually get that information.
A credit card proves nothing at all about the user: It's like saying the car owner's age guarantees the driver's age.
(Didn't downvote you though.)