When I upload a file as a visitor (i.e. not logged in), the file get no author. It's fine for me, but when I approve it through the manager, it sets my user as the author of the file.
Could it be possible to force it to be "visitor" (for example, but maybe it's impossible for WP to set it at a non-existent user...) at upload ?
Or maybe add some info via filters to let us know that, in our big media library, this file was uploaded via frontend uploader ?
Anyway, the plugin works like a charm !