In recent times, we've seen quite a number of major leaks in regards to video game content. Joining the leaks for The Last of Us Part II's story cutscenes, and the source code for both Pokemon Gold and Silver and Team Fortress 2 is a collection of Nintendo-related content. Supposedly, RouteFree, the company behind Nintendo's iQue Chinese division, and BroadOn, a company that assisted Nintendo with the development of the Wii, were recently hacked, leading to a source obtaining various files from them, including source code and betas.
Included in the files was information about how Nintendo created the Wii itself, demos for games that they used to test the Nintendo 64 during development, the full source code for the Nintendo Wii's IOS, a handful of pictures and documents about Nintendo's plans during the years of 2004-2006, the iQue GameCube SDK, and much more. Certain users have already begun uploading videos of some of these leaked demos running on emulators or official hardware. Just as with the other leaks, you cannot link to the content or distribute it, as those files contain copyrighted content.