If you have a google account for g+ or gmail, or even youtube, then you might have noticed the whole "We have changed our privacy policy". What does that mean?
Since I hate reading like anyone else I won't go much into detail here, but did you ever notice that when you are logged into your google account the searchengine itself knows which sites you have been visiting and when?
So for laughs, go to http://www.google.com/history
See what I mean? But do not worry, incase you dislike the thought that google keeps recording every embarassing bit of your surfing attitude (why would someone not want to have their habits recorded by a huge company?

So yeah, you decide what to do with this.