According to various rumours Nintendo has plans to disable 3DS units that have used flash cards.

When it was announced that the 3DS was hacked to accept flash cards for the original DS games some claimed it showed Nintendo hadn't tried hard enough to protect the 3DS from piracy. However, according to various rumours compiled by GoNintendo this was part of their plan.

According to the rumours the 3DS can keep a log of flash card usage and retailers can check this and deny any trade-ins. Furthermore, there are rumours that the 3DS will receive an update that will prevent any units that have used a flash card from booting up, meaning the console itself will become useless.

A related rumour suggests that a future update may also prevent curse words being used on the console. At present the console will accept profanities when naming things but Nintendo may prevent this in the future.

Of course it is unlikely Nintendo will outright confirm these plans so we will have to wait and see what future updates bring.