I see this when an Adblocker is active. The videos seem to detect that and won't play.
I have a Mac Pro w/ OS X and can watch YouTube video content w/o issues, along w/ Netflix content, but can't watch video content on the CNET site.
The Adobe Flash player is current. I am sure this is a simple fix, but so far no luck on my end.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic