How to create protected video embeds?

How can I create a system similar to yours, where in order for someone to use the video embeds, the have to register their domain name with the seller? This may be a good way for me to protect video content from being shared on other sites which are not part of my customer base.

I just discovered this product. Does anyone know if it would work well within the WPMU membership plugin and related plugins? http://www.armandmorin.com/padlock/

Dustin