[Greasemonkey] Any way to do stuff before the DOM is fully loaded?

[Lenny Domnitser]

Greasemonkey always executes at DOM load, probably after the evil JS
already executed. However, there are still ways GM can help you. Try
turning off Javascript and looking at the page source (maybe headers
too--I'm not familiar with AtomFilms specifics) to try to find where
the media is located. Then, even if you're told that you can't watch
it, you can insert a link to the file.