copyright

Q: I downloaded some IELTS learning books from Torrent which I dont know is copyrighted or not... After learning through them I am gonna start a spoken class and charge students fees...is it halal??

Q: If any author kept his book (not Deeni) on certain rate to download online (book for sale), the same book I get from another source some other guy downloaded before and posted on his site or from torrent. Is it ok to download that books and read it and get knowledge from it and it helps for my career. If the author is dead and the caretaker selling the book online. Can I download it from another source, I don't know weather they buy or just download it illegally and posting it for free.

Q:  I purchased an ebook from a seller who has stipulated copyright laws in the ebook. Is it permissible for me to share this ebook with others via email, WhatsApp, etc.? If someone else shares the book with me, can I download it and make use of it?