According to that third YouTube link, which was uploaded two weeks ago, this was discovered by a YouTuber named ShadowTheRoadhog.
I asked because, well, I think I was involved in the widespread dissemination of this, without meaning to.
Someone posted it over on the Nintendo Database forums, and I noticed it and mentioned it on NeoGAF.
The next day, it was plastered all over the blogosphere.
It was slightly scary.