Yep, Magic Banana hit it on the head - It's automatic with "Whoopsie"
http://askubuntu.com/questions/135540/what-is-the-whoopsie-process-and-how-can-i-remove-itAnd it's talked about in the last 10 minutes of the video Magic Banana linked to:
https://www.youtube.com/watch?v=_WW0Dz079lg&html5=1Note that I modified the URL to include &html5=1 at the end so you automatically get it as WebM. (Why don't more people tack that on to their URLs when sharing YouTube videos?)
