Earlier this month a rogue iPhone developer had managed to hack into a number of users' iTunes accounts in order to increase sales and boost the chart positions of his book apps.
The developer has now been named, shamed and banned from the App Store by Apple for violating the Developer Program License Agreement.
Thuat Nguyen managed to get 42 of the top 50 book apps in the US iTunes Store, which immediately triggered suspicion within Apple and the app development community.
iTunes security tips
Apple has confirmed that around 400 iTunes users were affected, which, even though a small percentage of the 150 million-plus daily users, is still 400 too many.
"If your credit card or iTunes password is stolen and used on iTunes we recommend that you contact your financial institution and inquire about canceling the card and issuing a chargeback for any unauthorized transactions," reads an Apple statement.
Trudy Muller, an Apple spokeswoman, was keen to stress that there has been "no hack into iTunes"
Ms. Muller also stressed that developers received no confidential personal information about iTunes users and noted that Apple will ask users to enter their credit card security code more frequently.