There's no technology that's 100% safe from fraud or social engineering. Those are predators that walk the cyber landscape, and just like hunter gatherers had to watch out for saber-toothed tigers and dire wolves, modern consumers have to keep an eye out for scammers and spammers.
So, it comes as little surprise that Fox New York (via Consumerist) reports iTunes is among the many attack vectors Bad Guys use when committing their fraud.
The crux of this one is bogus charges on your credit card, from $1 to full on $50+ gift card purchases:
Over on GetSatisfaction, there's a long thread about fraudulent iTunes charges, but no clear answer about what's going on. In fact, some people seem to be getting hit with charges on their credit cards from a fake APL*ITUNES business even if they don't have iTunes accounts, while others who do have iTunes accounts receive receipts via email for real gift card purchases that they didn't make.
So stay informed, check your accounts and your credit card charges, and report anything fishy (or phishy).