<< If you use the YouTube Embeddable Player on your website, you must include a prominent link back to the YouTube website on the pages containing the Embeddable Player and you may not modify, build upon, or block any portion of the Embeddable Player in any way.>>

http://www.youtube.com/t/terms

> a prominent link back to the YouTube website

Well, as the player itself is a "link" (you can click on the video to be taken to the YouTube video page) that should settle that. Otherwise, people can handle it like YouTube: embed first, remove only when asked by owner :)