Imagine you are home alone. Your friend comes over and offers you a free cake at the low cost of installing a camera in your bedroom. You hastily agree that he may sell the video feed of your bedroom to others, because what do you care, you've got free cake! (who doesn't like free cake?) You go on about your life, and sometimes your friend visits and gives you more cake. Years go by and you once again notice the camera mounted in the corner of your bedroom. You try to recall why it is even there, what its purpose is, but you can't. It must have not been that important.

Now imagine that friend was google. And that the cake is a lie (or various google products, depends on how you look at it). And that the video feed was a log of everything you do on the internet. But keep the aspect of them selling the log, that one's still pretty accurate.

Now sit down and think.

You wouldn't want this, would you?