I would like to discuss a very current topic which is relevant to those who shop on the Internet. Rabbi Yechiel Wasserman (Techumin 18: 248-251) discusses whether one can make a Halachically valid Kinyan on the Internet. There are a few Kinyanim that we need to explore in order to arrive at a legitimate conclusion.
The Basic Kinyan
The Mishna in Kiddushin (1:5) states that one can make a Kinyan on property that has security (real estate) with the following three devices: money, a document, or a Chazaka (demonstrating ownership by effecting a change on the property). On properties without security (/)-)-*0 - movable property), acquisition is accomplished through Meshicha. There are three elements of Meshicha (see Ritva, Kiddushin 25b s.v. V'havi). The first and preferred method is %#"%%, where the owner lifts the desired object as a symbol of acquisition. Meshicha, which literally means pulling the object, is quite common because there are many objects which cannot be lifted, so it is the best "substitute." Mesirah, which means handing over the object, is done when the other two methods are not feasible. In addition, Hagbahah is effective anywhere, unlike Meshicha and Mesira, which are effective only in certain places. There are a few conditions that apply to Kinyanei Meshichah: a) there must be a set price affixed to the item b) the presence of the item is required and c) the item must pass from the owner to the purchaser. All Kinyanim also require knowledge and intention of acquisition, #/*9; $3;.
A Modified Kinyan
In Vayikra (25:14), the Torah describes selling or purchasing an item from the hand of his friend. The Gemara (Bava Metzia 47b) cites Reish Lakish, who argues which acquisition is passed from hand to hand - Kinyan Meshicha! Rabbi Yochanan, on the other hand, argues that Kinyan Meshicha is merely a rabbinic law. Kinyan Meshicha is the basic acquisition device, but there are other methods that differ from Meshicha. Kinyan Chalifin is one such technique, where the two parties participate in a barter transaction and it is only necessary for one party to do an acquisition in order for both to own their respective desired items. Kinyan Sudar is possibly an extension of Kinyan Chalifin. Here one need not even have the object present in order to acquire it - the purchaser hands a symbolic utensil, such as a handkerchief or a pen, to the seller to effect the transaction. The text in Megilat Rut (4:7) serves as the biblical source of the Sudar, as displayed by Boaz acquiring an item by removing his shoe and handing it to the #&!-. Kinyan Sudar became very popular because of its rudimentary process and in the times of the Gemara was simply referred to as "Kinyan."
An Inventive Kinyan?
The final Kinyan that we will discuss is very controversial and there are various interpretations regarding its meaning and use. It is called a Kinyan Setumtah. The Gemara in Bava Metzia (74a) first makes note of it in analyzing a dispute between Rav Chaviva and the Rabbanan. Rav Chaviva views Setumtah as a valid Kinyan, while the Rabbanan are of the opinion that it only allows for a "Mi Shepara" a censure meted out by the Rabbis in order to prevent broken verbal or non-Halachically binding agreements). Rashi defines the Setumtah as a signature (mark) by the wholesaler after acquiring a large shipment in order to identify his merchandise. Rashi explains that this procedure renders a complete Kinyan and in fact many merchants did use this method as a means of acquisition. The Ritva, on the other hand, claims that this "Setumtah" was really a token symbolizing the purchaser's acquisition of the item. He argues that this only serves to effect a censure. Rashi believes that since the merchants accepted "Setumtah" as a device for Kinyan, it is valid. Rashi agrees with the Rashba (ad loc. s.v. Ub'duchta), who concludes that a Setumtah is effective since a Minhag can override a Halacha. Ritva, though, disagrees with both Rashi and Rashba and therefore voids all acquisitions made by a Setumtah. Rambam confers with Rashi and states in Hilchot Mechira (7:6-7) that if it is the custom to acquire merchandise via a mark, it is acceptable as a Kinyan because a Minhag can override a Halacha. One may explain that since Setumtah is in the family of Meshicha the same guidlines apply - there must be a set price and the item must be present. The Shulchan Aruch (C.M 201:2), though, indicates that Setumtah is similar to Kinyan Sudar, and consequently the presence of the desired item is not required.
One should note that the Teshuvot Dvar Avraham (1:1) understands Kinyan Setumtah differently than Rav Wasserman. The Dvar Avraham argues that the Teshuvat Chatam Sofer (cited by the Pitchei Teshuva 201:1) correctly asserts that Kinyan Setumtah is valid on a Torah level. The Dvar Avraham explains that Kinyan Setumtah is rooted in Kinyan Sudar. He marshals sources that demonstrate that Kinyan Sudar is effective because society accepts it as a Kinyan and not because the Torah mandates it. The Dvar Avraham believes that Kinyan Sudar is a manifestation of a Torah principle that whenever society accepts a particular act to be one which seals a deal, Halacha recognizes that act as a legitimate Kinyan. Thus, the Shulchan Aruch's ruling that the desired item need not be present for Kinyan Setumtah to be effective, similar to Kinyan Sudar, is readily understandable in light of the Dvar Avraham's assertion.
Obviously, these different views are vital in determining whether or not one can make a Kinyan on the Internet. Everyone agrees that knowledge and intent are required to effect the Kinyan and this requirement appears to be satisfied on the Internet. An action (clicking on the mouse) is performed to make the purchase, thus satisfying those opinions who require an action for Setumtah to be effective (see Piskei Din Rabbaniyim 4:289). The Ketzot Hachoshen (C.M. 201:1) and the Chatam Sofer, cited in Pitchei Teshuva 201:1, argue, however, whether one can make a Kinyan on an object which has not been created yet, which often is relevant to Internet purchases. A Posek must very careful when analyzing this situation because once we commit to accepting the Kinyan on the Internet we cannot turn back on this decision. Moreover, Rav Uri Dasberg wrote (in 1998 Techumin 18:251, note 2) that Internet purchases have only recently started and do not yet qualify as a Kinyan Setumtah. Once it has been tested in courts and accepted on a communal level, it can be regarded as a Kinyan Sudar. Rav Dasberg argues that until this happens, clicking on the Internet is regarded as a contractual undertaking, which is less binding than a Kinyan.
Postscript by Rabbi Howard Jachter
A serious issue that is often raised today is whether one may maintain one's website to conduct business transactions on Shabbat. Although this author is unaware of Teshuvot written on this topic, two important discussions serve as a basis for discussion of website operation on Shabbat. Dayan Yitzchak Weisz (Teshuvot Minchat Yitzchak 3:34) discusses the permissibility of maintaining a vending machine in a public area that operates on Shabbat. He notes many authorities (including Rav Akiva Eiger) that forbid taking title to items on Shabbat even if the transaction took place during the weekday. To avoid this problem Dayan Weisz suggests that the owner declare that he does not take title to the money deposited in the machine until after Shabbat and that the purchasers acquire title prior to Shabbat to the items that they will take from the machine on Shabbat. Prominent rabbis have expressed serious reservations about the validity of this solution to this author.
Rav Uri Dasberg (Techumin 19:349-363) discusses whether a bank may allow its automatic teller machines to operate on Shabbat. Among his suggestions is arranging that the machine display a message urging customers not to use the machine on Shabbat. Prominent rabbis have expressed serious reservations about this suggestion as well. Indeed, Rav Dasberg notes that the late Rav Shlomo Goren forbade Bank Hamizrachi to keep its ATMs in operation on Shabbat. Accordingly, one should ask his Rav for a Halachic ruling regarding this serious Halachic issue.