disabling icons presenting content

[Sim Tov <smntov gmail com>]

Hi,

1. how can I disable icons presenting content (like icon of an image
file showing that image in small format in the file manager) system
wide. Users should not be able to enable it back.

2. I have made files in some folder unreadable. When I copy an image
file there (that normaly presents its content with its icon) its icon,
as expected, stops showing the image. the same happens to videos.
however mp3 that have an embedded image are shown with icons
displaying this image. the mp3's themselves are not playable... how
can I disable images in the mp3 files icons?

Thank you.