Lewis Galoob Toys, Inc. v. Nintendo of America, Inc.
What does that case have to do with anything I said???
The game genie is a cheating device, Nintendo sued Galoob in grounds that it was violating their copyright, the judge declared it didn't... Thanks to that other save dongles exist such as Powersaves pro for 3DS which is legally sold everywhere because it doesn't have Nintendo's copyrighted material anywhere.
It wasn't a piracy enabling device such as Gateway or Sky3ds which are ilegal because they violate copyright.