An Apple rep has just confirmed to Engadget that one developer, Vietnam-based Thuat Nguyen, violated the Program License Agreement in a way that rigged fraudulent purchases of his e-books. All of his apps have been removed from the store.
Apparently, only a few hundred users were impacted by Nguyen's actions, but some users were charged as much as $600 for e-books they never purchased. As a precaution, we recommend checking your iTunes purchasing history and any linked credit card account to ensure that you were not affected by this scam.
However, if you were inadvertently part of this fraudulent activity, you're pretty much on your own as far as recovering lost funds and maintaining the security of your iTunes account. Apple said you'll have to contact your bank about chargebacks and change your iTunes password; the company didn't offer any special help or reporting mechanisms.
Various reports around the web indicate that the e-books in question were of suspiciously low quality to begin with. Between this factor -- which should have surfaced before the e-books even hit the App Store -- and the fact that Nguyen's books rose so quickly in sales rankings, we wonder if this fraudulent activity couldn't have been stopped earlier or prevented entirely.