Stealing and photocopying

Question

Shimon has in his vault a valuable document. Reuven knows everything there is on this document, but he wants a copy of it anyway. He's only going to use it for personal use, not to sell it. Being the nice guy he is, Reuven asks Shimon for permission to see this document. But he photocopies it while he has it, say for future reference. Now, when he returns it, he mentions to Shimon, "By the way, I hope you don't mind that I made a copy of your document."

Shimon is understandably annoyed by this act, but he's not sure there's anything he can do. Did Reuven violate lo signov? No. He had the document legally. Is there geneivas da'as? No. Shimon gave it to him willingly.

So: is there an issue with copying someone else's objects, assuming that there's no geneivas da'as or actual geneivah? What about in a case where Reuven decided to copy it only after he had it in his possession? Is that a Sholeiach Yad issue?

Answer 1

Mordechai (Bava Metzia 293) writes:

המפקיד ס״ת אצל חבירו גוללו כל שנים עשר חדש ולא יקרא בו לכתחלה. פי׳ רב יהודה גאון כשם שאסור לקרות בו כך אסור להעתיק ממנו אפילו אות אחת שלא ברשות משום דמרע ליה לפקדון וה״מ בבור ועם הארץ אבל חבר ות״ח מותר לקרות בו ומותר להעתיק ממנו ואפילו לכתחלה שלא ברשות והוא שאין לו כיוצא בו לפי כשהפקידו אצלו יודע היה שהנפקד חבר וילמוד בו ואדעתא דהכי הפקיד אצלו

[In the event that] one deposits a Sefer Torah in his friend's house, it is to be rolled once every twelve months, and he may not read it l'chatchilah. Rabbi Judah Gaon explained, just as it is forbidden to read from it, so it is also forbidden to copy even one letter without permission, because he [thereby] ruins the deposit.

[The above] applies to a boor and an am ha'aretz (ignoramus), however a chaver and talmid chacham is permitted to read it and likewise to make a copy from it, and even l'chatchilah [he may do so] without permission. This is provided that he does not have anything similar to it. [The reason it is permitted is] because when he deposited it by him he knew the depositee is a chaver and will learn from it, and it is with this in mind that he deposited it by him.

Thus, if it is something that Shimon can reasonably expect Reuven to copy, it would appear according to this that it is permitted.