Over the weekend a nefarious Apple "developer" managed to capture 42 of the top 50 sales positions in the App Store's "book" category with apparently bogus content -- and possibly sales.
Thuat Nguyen, from the suspiciously-named "mycompany," released a series of book apps in April that had little or no ratings or reviews and what appears to be artwork co-opted from Dragon Ball.
It's not completely clear, but it appears that the increase in sales may have been due to hacked iTunes accounts that were used to purchase the bogus titles in question.
Apple has responded and tacitly acknowledged that fraud may have occurred:
The developer Thuat Nguyen and his apps were removed from the App Store for violating the developer Program License Agreement, including fraudulent purchase patterns.
Developers do not receive any iTunes confidential customer data when an app is downloaded.
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. We also recommend that you change your iTunes account password immediately. For more information on best practices for password security visit http://www.apple.com/support/itunes.
Update: Apple has confirmed to 9to5Mac that 400 iTunes accounts were indeed compromised in the incident (a tiny fraction of the 150 million accounts) noting that Apple's iTunes servers weren't compromised.