More than a few of us (and us) noticed that when you got the latest update to Angry Birds, the app stated that it needed permissions to your SMS messages. At the time, Rovio told us it likely was a mistake, and that they'd look at it on Monday. However, it turns out it has a purpose and is part of an in-app payment system, called Big Bad Piggy Bank, which can be used to purchase the Mighty Eagle and other content. From Rovio's blog:
Bad Piggy Bank purchases will be paid through operator billing. No credit card is required, you simply select the content you want to purchase in the game, and select the Bad Piggy Bank icon. You confirm your purchase, the payment is made via SMS, and you will be charged in your phone bill.
The Android version of Angry Birds asks for SMS permission because this mobile payment capability has been added in version 1.5.1.
Angry Birds does not use the SMS functionality of the device for any other purpose than Bad Piggy Bank payments.
If the Bad Piggy Bank is not available for your operator, no purchases can be made, and you cannot be charged for anything.
All that said, it's only available in Finland at the moment. And note that this is separate from the in-app billing that Google just announced with Honeycomb.
So the good news is that there's nothing malicious (not that we ever thought there was) in the update. The bad news is it gives the app a permission that so far a very large number of users can't actually use. [Rovio] Thanks, Justin!