I don't have a link, but I've noticed that quite a few videos in the similar corner of topics need an "age check" (e.g. https://www.youtube.com/watch?v=_2khAmMTAjI , the creator of which was (according to them) visited by DHS for "anti-american sentiments" [1] )

[1] https://twitter.com/_secondthought/status/133274615894763520...