After a while I figured this out. The best way to tackle the problem is to first have a member system where only authenticated users can access the content and embedded files. Then all you need to do is include the media via an expiring url. Here is the PHP snippet I used:
http://snipplr.com/view/46753/amazon-s3-expiring-link/
Make sure the ACL file settings are set to private. A member can then access the link to download the file/watch a video. If they copy the url of the media they cannot share with friends because the link only lasts for a set period of time.