Daas,
Do you disagree with what I maintain is the maximum recourse available to the producer under halacha if the “renter” violates the terms of the agreement? (If so, specifically on what halachic basis?)
Yes. A rental has a return involved, the agreement is that it must be returned if copied.
IOW, you agree with me that the only recourse the producer has (if the renter makes a copy for his iPod or for his friend thus violating the terms of the rental) is to demand the CD be returned, but disagree with me that the producer must issue the customer a refund (i.e. a pro-rated refund based on the remaining portion of the rental term — originally 20 years in Aderet’s case).