They claim you can set your videos to "private" on YouTube, embed them on your website and prevent them from being shared. They claim their plugin consists of three components, YouTube API Client, WordPress plugin and an application located on their server.
They state and I quote, "This plugin is*completely compliant with YouTube's Terms of Service. The plugin is not accessing any YouTube Content through technology or means, other than what is explicitly authorized by*YouTube."
If what they claim is true, this would be the answer to embedding private YouTube videos on your membership site.
What do you think?