Just wanted Websense support to check into this. I love the fact I can limit or block viral videos. Recently in Chrome I noticed a red progress bar at the top of Youtube pages. I also notice viral video were no longer blocked. But this was not the case for IE or in Chrome on some other computers. Then I found a blog site mentioning Google's deployment of a new Ajax based interface for Youtube.
http://googlesystem.blogspot.com/2013/08/youtubes-ajax-interface-live-in-chrome.html
I think Google is still testing this, that is way it's randomly happening on some computers. Either way when this launches it will break filtering of Viral Videos in Websense.