I'm not sure what X-Frame-Options has to do with it. I'm suggesting either not allowing rendering of bitmaps containing different origin iframes/images, or blan

I'm not sure what X-Frame-Options has to do with it. I'm suggesting either not allowing rendering of bitmaps containing different origin iframes/images, or blanking out those elements in the rendering. Canvas does exactly that by not allowing different origin images to be drawn into a canvas element.