You mean a live feed of a server?
No, I think he means a mod that plays youtube videos on a server.If this is it, then this cannot be done; The game could download the video, but would be unable to play it as I am unaware of any method to play videos in-game.
Get a GuiAviControl and put it on the playGUI, then when the video is done, delete it.
Issue is, you have to make everyone download the potentially large file.
Mmm..
And possibly controversial, including MLP and research (and some even more questionable combinations of the such).
Then you ban them/leave the server?