Similar to Facebook, some applications you may use on your BlackBerry are able to access personal data information stored on your phone, such as your e-mail address. Many users did not know that applications were using their personal data and within reason, many are concerned about how that information is being used. For the most part, app creators use your e-mail address simply to market new apps to you - you'll find this predominantly on apps that are free to download.
I'm going to show you how to edit your permission settings for apps so that your personal information stays personal.
Options > Device > Application Management > Menu > Edit Default Permissions > User Data > Deny
By doing this, you will now be prompted if any software is trying to access your personal information and you will be asked if you'd like to allow this or not.