I've only made multi-item purchases from iTunes a few times, but every time I've gotten a call from my credit card company within a couple hours. The last time they said that it's become so common for fraudulent activity on a card to start with a "run on iTunes", then move on to other online sites if the card still works.

The only thing I would recommend to Scott Hansleman is to drop PayPal. They can be easier for small donations online, but with how far behind the curve they are in consumer fraud protection I refuse to make purchases with paypal anymore.