Nintendo said: The Nintendo WFC ID and the game card are treated as a unit. Because of this, playing your Nintendo DS game card in another Nintendo DS system may override all of your online information saved to the game card, including your own personal Friend Code. Other players with this Friend Code would no longer be able to identify you as an online friend until you provided them with the new Friend Code you would need to generate. We recommend against playing your Nintendo WFC-compatible DS game cards in any one else's Nintendo DS system.

Wikipedia said: [Per-game friend codes and the pairing of the Friend code and system] are conscious steps to preserve users' privacy. For example, if one sells a DS game, but not the system, there is no risk of the purchaser impersonating the seller.

Yekolf said: its annoying, my security isnt WEP its like WEP-A454, somthing like that so it wont let me do wifi