Moreover, Nintendo & co. would have sued them into oblivion ages ago if they actually believed to have even the slightest chance to win. Still the various Snes9x, Zsnes, VBA, FCEUltra, Dolphin ecc... stand, and some of these are decade's old projects. Even in their own "Legal FAQ" Nintendo is very harsh against emulation but never claims that emulators are illegal, even when they discuss about emulators "made to play illegal games". They do instead claim very explicitly that ROMs downloaded from Internet and "Game Copying Devices" are illegal.