If your worried, because Google is collecting your data through, "When you visit Google.com, YouTube, or any site with Google Analytics, chances are you've picked up some Google cookies during your browsing." If you want to know when that's happening, Google Alarm is the Firefox or Chrome add-on for you that visually & audibly alerts you whenever your personal information is being sent to Google servers.
Also, you've alternatives, like Ghostery, that offer similar alerts and the option to stop your data from being sent when you don't want it to. And, BetterPrivacy, which focuses on removing never-expiring cookies like the ones Google uses.
Download: Google Alarm