Youtube changed this; does not work anymore.
Long ago I noticed one video on Youtube, which I could see when it was embedded, but not on its normal video page. There you could see the message:
Title of the Video This video blablabla Content, for you blablabla
To see the video you would need to login into an account where you set your age to 18+.
After some tests one can say that most videos can be viewed with this trick :)
nidx/yt18/ (does not work anymore, but still works with mpv)
Just rewrite it from
Search for “embed youtube video” in your $SEARCHENGINE …
I know, you can create an account and set a wrong age, but the url rewriting is very helpful in conjunction with a slow proxy.<br />Also I wonder in many cases, why Google “censors” such videos…