You merely purchased a license to listen to the content on > the medium you paid for.
I read, somewhere, that licenses, or End User License Agreements (EULA) may say you are only liscencing but there was some landmark case about 5 years ago where a judge ruled against it. This allows people to now resell their software legally. Anyone have more clarification on this? It sounds to me like its not a legally binding agreement. Otherwise wouldn't it be illegal for me to sell a used copy of my software on ebay? Or has that become illegal while I've not been watching?
