After completing the study of Talmud tractate Yoma, I would not have thought that rabbinic sources were sympathetic to protection of intellectual property, especially when the owners used their possession of the secret to earn high income at the expense of the public interest. For example, the Gemara at Yoma 38a tells us that the rabbis tried to get the Family of Garmu -- who were the makers of the Lechem HaPanim (the shew bread) for the Temple -- and the Family of Avtinas -- the makers of the incense for the Temple -- to surrender the secret recipes for their products for the "honor of Hashem." Both families refuse, and the rabbis attempt to have others attempt to reproduce the products with unsatisfying results. The holders of the trade secrets are then brought back with increases in their wages. Another story, at Yoma 84a, has Rabbi Yochanan publicly revealing the trade secret cure for a disease called Tzafidna, against the owner's wishes, on the grounds that it was in the public's interest. One would think, from these gemaras, that the rabbis today would not be supportive of protecting intellectual property. But according to a lecture by Rabbi Yitzhak Grossman, a rebbe in the Greater Washington Community Kollel, and my subsequent readings, rabbis over the past 200 years (and before) have been very supportive of protecting owners of intellectual property either based on a fairness doctrine of shuftim or under the concept of dina d'malcusa dina (respect for civil law in business law situations). Since I could not memorize on the spot Rabbi Grossman's examples and citations, I've reviewed some that are available on-line.
According to an article by Rabbi Israel Schneider, manuscripts published as early as the 17th and 19th centuries of the common era had haskamot (approbations), that served two purposes -- attesting to the erudation and competence of the author, and placing a temporary ban on publication of the author's work by any other publisher. Schneider cites a story from the Chasam Sofer (Responsa Chatam Safer, Choenen Mishpat, no. 41) which the latter believed was the source for the practice. That case involved Rabbi Meir Katzenellenbogen of Padua (known by his acronym, Maharam) who had published an edition of the Mishneh Torah in 1550-1551. Soon thereafter, another publisher, a non-Jew, printed another cheaper version of the same work. Rabbi Moshe Isserles (Ramo), in addressing the issue, invoked the rule of Hasagat Ge'vul - legislation which protects one's commercial rights from undue competition - in declaring a ban upon anyone who purchased the rival edition of Mishneh Torah. That ruling, said the Chasam Sofer, ushered in the era of rabbinic haskamot which embodied, by force of ban or excommunication, protection for the rights of publishers of religious works. Just three years after that controversy, the Rabbinical Synod of Ferrara enacted a regulation that the first edition of any book written by a Jew must receive the approbation of three rabbis. It was Rabbi Meir Katzenellenbogen who headed the list of signatories.
The Chasam Sofer, however, explicitly rejects the idea that the purpose of bans was to protect the original publisher, but rather to protect incentives for authors to write books of Torah. He wrote:
If we were not to close the door in the face of other publishers [i.e. prohibit competition], which fool would [undertake the publication of Judaica and] risk a heavy financial loss [lit., a loss of several thousands]? The publication [of Jewish works] will cease, G-d forbid, and Torah [study] will be weakened. Therefore, for the benefit of the Jewish people and for the sake of the exaltation of the Torah, our early sages have enacted...
Responsa Chatam Sofer, Vol. 6, no. 57.
Rabbi Grossman, in his lecture, gave similar examples. For example, he noted the case of one author who had written his own commentary to a Tractate of Talmud and then hired a publisher to reproduce the Tractate with his notes added to other traditional commentary. The author painstakenly checked and rechecked galley proofs until every page was perfect and ready for printing. Soon thereafter, the printer -- having all of the proof-read pages type-setting casted in blocks -- tried to publish his own Talmud volume minus the author's new commentary. The rabbis ruled that the printer was taking advantage of the sweat-labor of the author in proof-checking the printer's type-setting, and therefore the printer was effectively stealing the labor of the author.
In contemporary halacha, there are different approaches according to an article by Rabbi Doniel Neustadt:
In a view that mirrors a recent Supreme Court case, Kirtsaeng v. John Wiley & Sons, Inc, 133 S.Ct. 1351 (2013), rabbis have held that a purchaser of a book or other item of intellectual property has unrestricted use of that product and, for example, can lend it to a friend or resell it. But see Chasam Sofer C.M. 2, who debates this question.
Some poskim maintain that it is halachically permissible for one to benefit from "intangibles" such as another person's idea or invention. Once the creator has committed his wisdom or talent to paper or tape, he no longer owns anything of material value. If so, nothing tangible is being taken away from the rightful owner. Beis Yitzchak Y.D. 2:75. However, where the creator creates his intellectual property as his source of income, making copies of the work would violate halacha if it impairs the creator's income. Those who follow this theory base it on a position found in Tosafos Kiddushin 59a. See, e.g. Rashdam 259; Chasam Sofer C.M. 79; Parashas Mordechai C.M. 67; Nachalas Tzvi C.M. 237. Maharsham 1:202.
Another approach, found in many recently-published Jewish works (especially Art Scroll), is for the creator to retain certain rights of ownership by explicitly prohibiting copying. This makes the sale a contingent sale to which the purchaser must agree. This argument is advanced by Rabbi Z.N. Goldberg in Techumin, vol. 6, pgs. 181-182.
Among some of the most famous poskim, there are nevertheless disagreements. Rav Moshe Feinstein forbade the copying of Torah tapes holding such acts to be a form of thievery. Igros Moshe O.C. 4:40-19. However, Rav Shmuel Wosner held that it was permissible to make photo-copies of individual pages of a book for classroom use even though, in theory, that deprives the author of multiple sales. Shevet ha-Levi 4:202.
Following Rabbi Grossman's lecture, I asked him if the gemara in Yoma, cited above, were distinguished or discussed by any of the poskim who would restrict intellectual property. He said that he could not recall any cases where they were, but he promised to review the sources again.