This argument doesn't really apply to software/music/movies. When you buy a car, you are paying for a physical object. When you are buying the software/music/movies, you are paying for the license (read those EULAs) to use an easily replicable string of bits. Taking another car would be taking money from the car lot owner. Buying a second license to use something when the first license still applies is just a waste of money. Furthermore, the legal backup of something one owns is generally accepted as being legal.Easy Street said:Piracy is piracy. Just because you paid for something doesn't give you a legal or moral right to pirate another separate item.
Its like buying a car and it breaks down. Do you feel you then have the right to go into a car lot and steal another one because you had already shelled out the money? Its the same argument.
However, downloading via something that also uploads at the same time (i.e. torrents) is illegal, because you are then distributing copyrighted information.