Amazon allows Appstore for Android developers to include digital rights management (DRM) code within applications distributed via its new software channel--though it does not mandate that devs use DRM. So while the choice to use DRM in an application goes to the developer and not Amazon, many apps in the Amazon Appstore will have DRM, and as such, they won't work on your Android devices unless: 1) You have the Amazon Appstore installed; and 2) You're logged into your account. (Read more details on Appstore DRM .)

Google's Android Market and the Android mobile platform itself have always been lauded for "openness." It's true that Google doesn't set too many restrictions on the use of software distributed through its Android Market. But even Google uses some form of DRM, at least .

For example, Google recently to automatically remove Market software from users' devices, after that software was determined to be malicious. And that wasn't the first time Google did something similar, either; last June, the from users' phones that were built by a security researcher.

Regardless, if you're looking to avoid DRM altogether, you may want to avoid Amazon's Appstore for Android.