But @mrtksn (the GP?) states that google
doesn't publish it, rather it's published by the author/uploader.
I think that's sophistry.
If I visit Youtube's website, search for "xyz", and play the first result, which happens to have been uploaded by "abc", that's analogous to visiting guardian.co.uk, and reading the top article on the page, bearing the byline "Paul Mason". Paul Mason didn't publish it; The Guardian published it.
The legal fiction that a system like Youtube or Faceache is not a publisher is to protect independent message-boards from being sued, e.g. for libel. But I think even a tiny indy message-board, with say 100 users and no income, is still a publisher. I don't see how you can draw a clear line between the tiny indy publisher and a giant one like Youtube.
And I don't see how you can draw a clear line between something like Youtube, and Guardian Online. Both publishers accept content submissions from multiple authors, review them (The Guardian perhaps not so much), and make them available to the public, possibly with amendments (e.g. overlaid or prefixed with ads).
So I'm sorry: I can't see how Faceache or Youtube is not a publisher, while The Guardian is.
If the laws relating to what you can and can't publish are wrong, then they should be fixed. But simply declaring that a system is a "platform" doesn't make it not a publisher, and doesn't fix the defective publishing laws.