ehh hmm I would think that Google could do this better and it would be done automatically and with a lot less effort. Creative Commons seems kind of pointless. Am I missing the point.
If you post material in the public domain such as to the "Web" then it seems that you could simply create a license like a software developer does, that is included in the download with the material. Then Google, WayBackMachine or site logs could be used in my defense of when I first published it.
Maybe creative commons should work on general licenses for the public domain instead of a protocol.