Vpham - NOT TRUE. If you are a minor, but REPRESENT yourself as an adult (ie by using a credit card, lying on an application, etc.) then YOU ARE RESPONSIBLE. The business does not have to verify your age, as you are representing to be of proper age by using a credit card.
A contract is voidable ONLY if the business dealt with you as a minor and you DID NOT MISREPRESENT that you were of legal age to enter into an agreement...moreover, if you continue to do business with them (ie making payments after you turn 18) the contract may be considered to be "ratified" and you cannot use the "minor" defense to get out of the deal....
Of course, with the new credit cards teens are allowed to use such as cobaltcard, visa Buxx, etc. which are given to minors, the parents/guardians assume liability...
Nothing in the law is ever as clear-cut as it seems.