Safari playing a youtube video in the background I start Safari, and after a few seconds, I hear what seems to be the sound from a video. (Sounds like a british guy playing minecraft) There are no windows or tabs open to YouTube or any other video site. The sound keeps playing as long as Safari is open. Closing tabs, clearing cache, clearing history all have no effect. The sound only stops when I exit Safari. When I start Safari again, the sound starts again from the beginning.

What is going on? How can Safari play a video if no tab/window is showing a video/video site?

Edit: And how do I make it stop?
You might want to try this solution from Apple's own forum (be sure to back-up your Bookmarks first):


  Open a Finder window. Select your Home folder in the Sidebar on the
  left. Now open the Library folder then the Safari folder.
  
  Move the LastSession.plist and the Downloads.plist files from the
  Safari folder to the Trash.
  
  Restart your Mac.


It also could be an extension messing up with Safari.