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.
If you believe that you are not permitted to copy copyright CDs, then you are not permitted to listen to it through the sites which permit this. It is your belief that should be taken into account, because you believe that these CDs are not owned by those sites and they [CDs] are still a property of its owners who prevented people from benefitting from it except with their permission.
Ibn Muflih from the Hanbali School of jurisprudence, said: “If a man had earned money in a manner which some people think is lawful and others think is ill-gotten money, like some kinds of trades, then it is permissible to deal with him in his money unless the person dealing with him (the man who earned the doubtful money) knows that this precise money is earned from a contract which is forbidden; in which case it is not permissible to deal with him in this money.”