Adding Brightcove or other embed code on WPMU by authors

I realize that it is a security issue to allow authors to embed videos from different sources and I have researched this problem to a great extent, so I understand it... However, there must be SOME way that I can enable a blog owner on my WPMU set up to post their own videos from whatever source they want if I trust them to do so. How can I best allow them to post the attached file (code) that is through an affiliate program...??