I'm guessing that it's related to Google Hangouts, which is integrated in every Google+ page. If you have the Google Talk plugin (or whatever it's called now)

I'm guessing that it's related to Google Hangouts, which is integrated in every Google+ page. If you have the Google Talk plugin (or whatever it's called now) you can do video chat right in the browser. Some bug with the drivers, I presume? (I have all the add-ons in Firefox 24.0, but no light for me)