Baba Metzia 78b - Copyright Law: Stipulation in the sale

The gemara says that according to R' Meir, if one deviates from the intention of the ba'al habayis, he is considered to be a gazlan. The gemara ultimately proves this from the case where one gives a dinar to a poor person and tells him that he must use it to buy a particular item. If the "ani" would deviate from the intention of the ba'al habayis and use the money for a different item, it is considered stealing from the ba'al habayis. Clearly, R' Meir holds that one may make a stipulation in a sale or gift to limit the use of the item. The rabonon disagree with R' Meir (as is apparent from out mishna where the reisha is r' meir, but the seifa holds that you aren't chayev for merely deviating which is the opinion of the rabbonon). Since we pasken like the rabbonon, the halacha is that a seller cannot limit the use of the buyer in an item. Perhaps the Rabbonon would agree that if one stipulated with a proper t'nai (following the details of a proper t'nai such as kaful, hein kodem l'lav...), then the seller would be able to say that if the buyer uses it in such way that is against the will of the seller, the sale would retroactively be void. However, in the absence of a t'nai, a seller cannot in anyway limit the way that a buyer uses a particular item.

This concept sheds some light on copyright law. When dealing with the copyright law there are really 3 issues that have to be considered. This gemara sheds light on the first of those 3 issues. The 3 issues are: 1. Can the seller limit the buyers use of an item? 2. Even if the seller cannot limit the buyers use, if intellectual property can be "owned" by torah law, one can argue that the seller never sold the intellectual property rights to the buyer. Therefore, any abuse of the intellectual property rights would be an act of stealing by the buyer. But, it is hard to find a source in the gemara that the torah actually recognizes this type of ownership. 3. Even if the seller has no ability at all to limit the buyers use of an item, perhaps the dina d'malchusa has a right to limit the buyers use to allow the market to function normally. This would presumably only apply to copying with the intention of selling, but if one copies for personal use, it is hard to explain how the government has the power to forbid this.

Now, in regard to the first issue: Being that we pasken like the rabbonon, the seller doesn't have any ability to limit the buyers use of an item that he purchased. If a seller would sell a cup to a buyer and insist that the buyer use if for coffee not tea, the buyer isn't bound by this stipulation. Similarly, if the seller says that the buyer may listen to a CD but not copy it, the buyer should not be bound by this stipulation (unless it was done with a proper t'nai that would void the entire sale retroactively, which is surely not the common practice).