All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The principle concerning this issue depends on copyright and similar rights. Our opinion and the general opinion of the scholarly councils and societies is that such rights are protected in Islam and it is not permissible to violate them.
Accordingly, if the videos which that site publishes are published in a way that involves a breach of the copyright, then it is not permissible to benefit from them or to learn from them.
However, some scholars are of the view that this is permissible as long as one benefits from them on an individual basis only, and not for the purposes of profit or the like. Please, refer to Fatwa 278614.
In any case, learning from materials that violate copyrights does not have any effect at all on the lawfulness of the earnings that a person gains from what he had learned from them. There is absolutely no relation between the two matters.
Allaah Knows best.