That recent DSi update that brought Facebook to Japanese DSi handhelds also brought something else: software to combat R4-type piracy devices.
Back in November of last year, it seemed as though R4 cartridges would not work in the then new DSi units. However, by May of this year, dedicated DSi piracy devices had hit the streets. Multip R4-type DSi-dedicated devices began appearing as well, making it possible to load downloaded games on to the DSi.
This latest DSi update seems to have once again nixed piracy devices for the DSi. According to one Japanese site, the update makes it impossible to use the following cartridges: DSTTi, Hyper R4i, ak2i, R4 Ui, R4i Gold, EZ Vi.
Last year, Nintendo and 53 other companies took action against the makers of the R4 cart, a device which allows, among other things, the pirating of games on a DS.
DSi FW 1.4J 人柱 マジコン対策 [NET ゲーム裏技徹底解説]