Update: I went through 4 or 5 pages (of 350) YouTube links and fixed them by removing the ] at the end of the link, so you see some code, but no impact to the video. These would be the most recent posts, if a few years ago is recent.
I will probably do all 45 pages of the specific "youtube'n" thread, but leave it at that. I think that's where most of the videos will be found anyway. Should you come across one you think important enough to fix, post here and I will fix that too.