The stolen one is gone. Again thanks for telling me.

Thanks. I'll take care of that.

someone stole your work and put it on the gmod workshop http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=499202432

he didn't even bother to fix it.

I'm not sure.

What you CAN do:
* Record what the security camera would see
* export it as a movie
* split it into single images (e.g. using Blender [blender.org])
* import these images to VTFedit as animted texture
* save it in usermod/materials/<wherever you want>
* add override materials
* change $basetexture to point to you texture

Quite complicated, but I'm afraid thats the only way.

Detonatress' Editable Computer Screens work this way too.

Yes, exactly. Like it's usable for a network of security cameras or a similar thing.

You mean so it displays the image of a camera in the scene?

Say, can you modify the texture so it can also have a skin that's usable as an RT camera?