Some of them have been uploaded on YouTube privately as “unlisted.”
But what I was saying was, clips should only be released privately - by private message - and only to trusted users. When I say "trusted users", I am referring to users who will not download the clips and upload them to their YouTube or any other video sharing site accounts.
Users who are interested should be screened before they get approved.
Personally, I don't think the unlisted uploads is working, and I do know that clips can still be downloaded even if unlisted, but not the case with private mode.
EDIT: I just realized that private videos can only be viewed privately by up to 25 users. Unless something's changed in recent years.