Board Thread:Questions and Answers/@comment-818260-20160608233432/@comment-5811199-20160609002851

Videos being turned to private often means there is a copyright dispute or something similar going on - it is a safety measure done by all of the Yogscast (you'll notice that some of MoonQuest is also privated).

They're more than likely working on restoring those videos as soon as possible, but yeah, there's nothing we can do :(