If a person has written a sefer and has obtained legal copyright of his work, does that make it forbidden for me to copy a dvar Torah or chiddush from that sefer and to distribute it for free to friends even if I inform them where the dvar Torah comes from? Do I have to obtain permission from the author to spread his Torah or is informing the recipients where it comes from enough? I am asking from a "purely" Halachic perspective of geneivah - without involving dina di'malchusa.
From the Business Halacha Institute:
Ownership of Torah Works
Q: Is there any difference between the copyright of Torah works and other intellectual property, such as music or secular works?
A: The Sho'el U'maishiv (1:44) applies full ownership rights also to Torah thoughts.
However, the Gemara (Nedarim 37a) states that, in principle, Torah teachings should be disseminated for free, just as Moshe taught Am Yisrael for free.
Based on this, some authorities distinguish between the copyright of Torah works and other intellectual property. Even according to the opinion that a person has actual ownership of intellectual property, they maintain that a person has only limited ownership or rights in Torah works. Beis Yitzchak (Y.D. 2:75) restricts the copyright to the first printing, which allows the author to recoup his publishing costs. The Torah requires teaching Torah thoughts for free, but it does not require the additional effort of writing or publishing for free.
Others compare the rights of Torah thoughts to tovas hana'ah (incidental benefit) of terumah, which allows incidental financial benefit through distributing the Torah thoughts.
Regardless, other reasons for copyright – e.g., dina d'malchusa and common commercial practice – would apply equally to Torah works.
(See Emek Hamishpat, Zechuyos Yotzrim ch. 6, 12)