In Utah, a minor can chose to repudiate (void) a contract at any time before reaching majority (18) and only have to return the material or money that happens to still be in their possession. The other party is left holding the bag, so to speak.
Hypothetically, a minor could buy a phone on contract with T-Mobile, sell the phone to a friend, and then tell T-Mob to pound sound when they tried to collect on the contract account.
No adult signed for the phone contract?
Or was the contract pre-paid or something?