I am making a game that utilizes GetPixel to build a billboard for 3D object. It worked fine with Unity2.x but now that I'm trying to upgrade the engine to Unity3 it began to conflict with the cross domain policy.

The problem is that I am downloading some external images for GUI usage -- to be more specific user photos from Facebook. I DO NOT utilize these in making billboards -- I use it only for GUI and no 3D object uses them. Yet I'm getting an exception when calling GetPixel using the render target texture. The exception message is as followed:

System.Security.SecurityException: Reading from the screen is not allowed when you have used a downloaded texture without proper crossdomain.xml authorization

Shouldn't unity check whether textures without crossdomain.xml are actually used for the scene rendering and generate such exception? Is there any workaround for this kind of problem?

I would appreciate any comments. Thanks!