RIM is taking steps to more closely control sideloading of apps on BlackBerry PlayBook tablets in an effort to prevent the spread of pirated apps. The new feature – due to appear with the next PlayBook update – encrypts apps so they can only be sideloaded by the person that purchased the app in question.

Sideloading enables developers to load Android apps onto their PlayBook devices in order to test them. However, it also allows consumers to install Android apps before native versions are released, creating the potential for pirated apps to be loaded onto PlayBook devices.

AllThingsD reports that a growing number of Android apps are being repackaged as free apps that can be run on PlayBook devices. The repackaging for Android is relatively straightforward meaning they can then be easily distributed and pirated, hitting developer income and reputation.

“[Sideloading is] there so developers can send a beta release to their testing community for review. It is definitely not there for some people to side load a pirated app,” said RIM VP for developer relations Alec Saunders on the Inside BlackBerry Developers Blog.

Saunders clarified that the company is not planning to get rid of sideloading for PlayBook OS or BlackBerry 10 completely and plans to work with the developer community so apps can continue to be quickly and easily tested on hardware.