It should be pretty damned obvious this is fake.
First off, tinyurl.com links all over the video. They're hiding something obviously. (Why aren't these links banned already?)
Secondly, approval on youtube can be bought, just people who will make accounts for the sole purpose of giving likes, comments and views to give the appearance of popularity and authenticity.
Thirdly, the video doesn't even show the hack in action, it's just some guy typing in Notepad.
SURE IS REVOLUTIONARY 3DS HACK IN HERE GUYS.