Nintendo is fighting against piracy so seriously for the DS because how "how much money the DS prints." The Nintendo DS is the CASH COW for NINTENDO. It is so great in fact, that there are alot of "homebrew enabling flash cards" made for the system that are not made by Nintendo. Because of this, Nintendo is not happy. Now their users can get the latest games for free and load them on the flash cards and never have to pay for another DS game. Thus the advent of Anti-Piracy/Coping software.
If I recall correctly, Nintendo now impliments Metafortress in all of their games now. However, this is easily disabled by loading the rom at 8000h.
Also, don't think that your Wii is immune to anti-piracy! The latest Wii games have complications when loaded with spicific loaders. Anyone remember the imfimus ERROR 002 for New Super Mario Bros Wii?
Also Nintendo combaits piracy with Firmware Updates. Both the DSi and Wii have updatable firmware.
Also, I doubt flash cards will be made for the 3DS because of the MANDATORY AUTOMATIC FIRMWARE UPDATES that the system does EVERY TIME IT SO MUCH AS PINGS A INTERNET CONNECTION.
tl'dr version:
Nintendo makes game, Nintendo Markets Game, People Buy Game, Nintendo Makes Money. Nintendo =
Nintendo makes game, Nintendo Markets Game, Someone copies and dumps game, People Download game for free, Nintendo Suffers losses. Nintendo = >(
When Nintendo = >( People get SUED!
I hope this elaboration helps.