If I remember, Nintendo had a statement backed up by American law stating that possessing backups of any of their games in any form (and any media) at any time (removing the 24 hour clause in some countries) from any source (downloaded or otherwise) is unlawful (using an aforementioned term).
That was for America, however each country/region has it's own independent law system and whilst many agree to the same laws, many also differ (language/culture/politics being some of the reasons for the difference). One such difference is that in the UK (from what I've heard from a few Law undergraduate friends) it is considered legal to create a backup from games you own for your own personal use (i.e. not sharing/distributing). This is simply because there is no specific clause against it in the UK, or so I am told, and thus it does not count as piracy.
As pointed out a number of times before, this debate is largely pointless and will not change anybody's behaviour. For the most part, pirates are unlawful and participate in some activities that may be frowned upon, but they're not doing anything criminal, so they won't stop. The worst they can actually do to you if anyone (namely ninty) decides to prosecute you, is confiscate the backups and/or the hardware (if it's hacked) and fine you the total cost (at RRP) of all the unlawfully obtained games.
The question that's been floating around isoHunt for the last few months is What kind of Pirate are you? There's the type that wants every game ever created for free and will download without any intention to pay. There's the type like me who "try before you buy", in downloading games to try them and only buy the ones worth playing. If I do buy the game, then I remove the downloaded backup and instead create my own backup (slightly more lawful). Then there's the type that will simply download backups of games they own just for the sake of having a backup if their games stop working.
There are other types, but I'm just giving an overview of the debate. Hardcore legalitarians (forgive the made up term) will say that a pirate is a pirate, even if the economic impact of their "piracy" is 0 (i.e. they buy the games they download). Moderate crowds will consider those with a low economic impact (try before they buy pirates) fair and are in fact increasingly encouraged by the gaming and music industry (although it wouldn't make sense for the film industry to support this).
I think everybody will agree that pirates who expect everything for free are the undesirable kind that has made this entire issue of piracy blow out of proportion. So I repeat again... What kind of Pirate are you? EDIT: Didn't 4chan come up with a variant of the ever-famous uncle Sam poster with the slogan "What kind of Pirate are YOU?"? It would be useful to link that image here if I could find it...