Apologies if this has been posted previously but I recently updated Adobe Flash Player and have started getting a pop-up when accessing a YouTube video asking me to let 's.ytimg.com' access my camera and microphone.
A quick search on the internet found this site (http://www.keiths-place.com/blogs/keith/2008/stop-youtube-sytimgcom-video-camera-spying) which gave this link (http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager02.html#118539) that enabled me to stop it and also had some other settings too.
Sounds like it's dodgy site if they're trying to spy on people watching the video. Report it to youtube if it doesn't clearly state they want access to this anywhere on the page of the video you're watching.
I recently received my Raspberry PI and was looking for advice on configuring it. I first noticed it on a YouTube link from either the Raspberry PI site or the users forum but I also got the 'pop-up' with other YouTube videos that Itried too. Since following the link to Macromedia support and selecting the appropriate options it has stopped doing it.