Praise be to Allah.
Copyright is one of the intangible rights that are protected by sharee’ah, as has been explained in the answer to question no. 26307.
There is nothing wrong with printing and selling religious books, because the basic principle is that it is permissible, and because it is a means of spreading knowledge, improving its quality and making it available to people, which cannot be done except by dealing in books.
Based on that, there is nothing wrong with printing any of the books of the salaf or contemporary scholars, unless their authors have not permitted it, in which case it is essential to have their permission, as well as to be trustworthy and honest in publishing these books. That also includes things that a scholar wrote without the aim of making money. It is permissible to print it and sell it and make money from it, so long as he did not object to that, in which case it is essential to have permission from him or his heirs.
It says in Fataawa al-Lajnah al-Daa’imah (13/187):
Question: Is it permissible to record a tape and sell it, but without asking permission from the author or, if the author is no longer alive, from the publisher, to record it? Is it permissible to make many copies of a book and sell them? Is it permissible to make a copy of a book and not sell it, rather keep it for myself? If the book carries the mark “All rights reserved”, should I ask for permission or not? Please advise me, may Allaah bless you.
Answer: There is nothing wrong with recording useful tapes and selling them, or copying books and selling them, because that is helping to spread knowledge, unless the authors have not allowed that, in which case it is essential to have their permission. End quote.
And Allaah knows best.