...review the sites you've allowed to access your microphone and camera in Chrome.
1. Open Chrome, and type chrome://settings/contentExceptions#media-stream into the Omnibar.
2. You'll see the Media Exceptions screen, where you can see which host names have permissions to your microphone and camera, and which of those two each site has access to.
3. Highlight any site you want to remove, and click the "x" on the right side of the line.
4. Save your changed by clicking Done.
PCWorld also notes that if you prefer, you can just go to: chrome://settings/content Scroll down to Media, and instead of "Ask me when a site wants to use a plug-in to access my camera and microphone" (which is the default setting), select "Do not allow any sites to access my camera and microphone," which is kind of the nuclear option.
Doing this will also disable features like Google's Conversational Search, which can be pretty useful, likely break any voice integration with Google Now (which will arrive in Chrome any day now), and disable any other voice-activated features in Chrome or elsewhere on the web. (more) (background)
