AI and Email Privacy
by R. Gil Student
Artificial Intelligence (AI) is increasingly shaping our world, raising new and complex questions. One such issue is whether it is permissible to use AI tools that analyze email and message content in order analyze trends without obtaining individual information. Consider an AI tool that reads people’s direct messages to analyze business trends and advises you on investment strategies. This tool can be perfectly legal but halakhah might be stricter. Are we allowed to benefit from AI analysis of private emails and messages?
I. The Cherem of Rabbeinu Gershom
Rabbeinu Gershom (11th cen., Germany) gathered leading rabbis together to issue a cherem—a communal ban—against a number of practices. Historians debate his specific role and the exact content and list of practices that fell under this ban, as opposed to later bans (Chakmei Ashkenaz Ha-Rishonim, p. 132ff). Regardless, there is a long-standing ban against opening and reading someone else’s mail that is widely attributed to Rabbeinu Gershom. The original context was physical letters, but authorities have extend its application to modern communication, including emails and text messages.
Rav Simchah Yonah Klein (cont., England) writes that the cherem applies even to hidden video cameras, i.e. nanny cams (Piskei Ha-Mishpat 154:7). Similarly, Rav Shaul Alter, in his recent book Software and Artificial Intelligence in Halacha, writes that “the cherem is not limited specifically to reading a letter, but to consuming any information that was not intended for public knowledge” (p. 334). It seems clear that emails and private messages fall under the cherem, as well.
Rav Chaim Palaggi (19th cen., Turkey) asks what rationale lies beneath this cherem? Even if the act is independently prohibited, Rabbenu Gershom and his colleagues may have enacted a cherem to reinforce the prohibition. Rav Palaggi suggests that it might be the obligation to love your fellow like yourself, or rather to not do to others what you would not want done to you (Lev. 19:18; Shabbos 31a). It might be a variant of gossip-mongering (Lev. 19:16). Alternatively, it might be a form of deception, geneivas da’as, or of using someone’s property without permission, which constitutes theft (Responsa Chikekei Lev 1:49). The distinctions between these different rationales will be crucial for evaluating the permissibility of AI that accesses private communications.
II. Rationales and Implications
Some authorities understand the prohibition as a form of theft by accessing someone else’s property, his information. Rav Chaim Shabesai (17th cen., Greece) writes that opening someone else’s letter is like borrowing something without permission, which is a form of stealing (Responsa Toras Chaim 3:47). In his recently republished book, The Practical Torah, Rav Michael Taubes writes that according to this view, “such action is forbidden even for the purpose of a mitzvah, particularly since one can cause damage to another by revealing his secrets” (p. 297).
According to this approach, if an AI accesses private email data without the owner’s consent, then the developers or users of the AI tool may be considered to have committed a form of theft. Even if no human sees the content, the act of extracting value from someone’s private correspondence without permission would still fall under the category of theft.
On the other hand, several authorities understand the core of the cherem not as theft, but as a violation of privacy. Rav Ya’akov Chagiz (17th cen., Morocco) briefly says that opening someone else’s mail violates the prohibition against gossip-mongering (Halakhos Ketanos 1:276). As mentioned above, Rav Chaim Palaggi suggests that this might be a violation of loving your fellow as yourself. However, both of those reasons would permit opening someone else’s mail when there is a mitzvah need to do so.
According to this approach, the violation is not the act of accessing information per se, but the act of disclosure. Meaning, the problem is violating the privacy of the individual. If so, an AI system that ingests an email but does not reveal the content, only extracting patterns or offering aggregate insights, does not violate the individual’s privacy. The secret remains hidden; no human sees it, no one exposes it.
For example, if an AI reads a team’s emails and determines that a particular merger will go through, but does not expose the personal content of any individual message, it might be functionally equivalent to a locked diary read by no one. The information is accessed, but the individual’s personal privacy remains intact.
III. Additional Considerations
According to our analysis, if reading someone’s mail is forbidden because of gossip-mongering, an AI would be allowed to analyze private correspondence and provide anonymized and aggregated analyses which could be used for business purposes. However, if it is prohibited because of theft, then even anonymizing and aggregating the information would still be forbidden.
However, Rav Yosef Shalom Elyashiv (21st cen., Israel) is reported as modifying Rav Palaggi’s analysis in a significant way. Rav Elyashiv’s son-in-law, Rav Yitzchak Zilberstein, presented a related question to him. Rav Elyashiv replied that opening someone’s mail can only constitute theft if the information is used to interfere with the victim’s plans. But if the victim does not suffer any loss, he has not been subjected to theft (Chashukei Chemed, Yoma, p. 55). If that is the case, then we would be allowed to invest based on advice legally extracted by AI from private emails and correspondence as long as it does not cause any damage to other investors.