You store the key in the source code as in the other poster's description of Youtube 1.0. So employees/contractors/etc could still see the number of total video

You store the key in the source code as in the other poster's description of Youtube 1.0. So employees/contractors/etc could still see the number of total videos and sequential order of uploads, but at least they can't enumerate them. You could also maybe rotate the key once in a while, but only for videos created after the rotation, and indicate the "key version" with a third field in the video ID