Sare that whole idea is fatally flawed, as millions of minors are walking around right now with their own debit cards that have Visa-compliant numbers on them and can act as credit cards.
Valid numbers does not equal 18 years old.
All a lawyer has to do is ask you if you own or have ever seen a Visa debit card, and you're done. Answer yes and you're screwed, answer no and you're lying (and also screwed).
