If I install the appropriate Firefox plugin, I see a "download" link. Does the TOS say that isn't a valid download link?
IANAL, but I suppose they could say that wasn't "displayed by YouTube" and then we get into the semantics and details of how a link is displayed and -- especially if you are a naive user using someone else's computer with the plugin installed -- how you can tell if the link you see is "displayed by YouTube."
Oh, but wait. I think this rabbit hole is already too deep. I'll stop digging.
----- Original Message -----
Yes, that's related to copyright and permissions of the material, but what about that first sentence:
You shall not download any Content unless you see a “download” or similar link displayed by YouTube on the Service for that Content
-Andrew Lih Associate professor of journalism, American University Email: andrew@andrewlih.com WEB: http://www.andrewlih.com BOOK: The Wikipedia Revolution: http:// www.wikipediarevolution.com PROJECT: Wiki Makes Video http://en.wikipedia.org/wiki/Wikipedia:WikiProject_Wiki_Makes_Video