Fraudulent debit
Every time I change password iTunes ask to type my card security code. The moment that happens my banks debits $1 for billing from iTunes!!!
a) it's not 'fraudulent'
b) it's not a real charge
When you use a debit card at a number of retailers (especially gas stations), they make a discretionary/temporary transaction of $1 to validate the card. The transaction is never confirmed, and does not draw any funds from your account.
About payment card authorization holds in the iTunes Store - Apple Support