Why do people think it's normal to film other people without their consent and put it publicly on Youtube? These guys are violating basic rights of these girls by exposing them on Youtube without them knowing. And if they are holding nude photos of them and sharing them, then it gets really worse, it's criminal.
Depending on where you are, different laws and rights apply. In Britain you're generally allowed to film in public places, for example (though I don't know where these videos were made specifically). The portrait or identity of specific people may still be protected, however. And they certainly are under EU GDPR. Thus, if you film without consent you are at the very least obliged to smear out the identity of people you've filmed. That also goes for their voice. (Though there are sometimes certain caveats in place for particularly newsworthy events, where the identity of photographed individuals can still be revealed, but these are normally exceptions.)
Posting nudes without consent is illegal in most countries, however. It's a horrible breach of trust that IMHO should be punished accordingly. And sorry in advance for moralizing but IMHO such activity does not serve our community either.