Quote from TGregg:
DLing something you would otherwise buy from the store is obviously wrong. But what about computer games that you buy then sell once you are done on eBay? It's morally wrong to pirate a game instead of buying and selling on eBay. However I wonder if the producers of the game really lose anything. You do offer a little bit of price support, so perhaps in a round about way there's a tiny amount making it into their pockets. But not much, if anything. Particularly if you are very careful when you purchase the game. If you are careful, you can sell it for a little more than you paid, so you are only out shipping, transaction fees and eBay fees.
I don't think buying something new/used and then selling a legitimate DVD/software is any more wrong than doing so with a tangible gadget. They were legal and that should not be a problem
The problem is, people decide to generate illegal copies and sell/upload those.
When you generates intellectual property and others decide to undercut you, then it changes your viewpoint.