Because those machines create a profile of you the likes of which the NSA would have a wet dream over. That profile can and will be used however Google wants'

Because those machines create a profile of you the likes of which the NSA would have a wet dream over. That profile can and will be used however Google wants' to use it. Remember, Google's (the company's) only reason for existence is to make a profit, and ALL their revenues come from Advertising - 96 percent. That's a hell of an incentive to know as much about you as possible, and use that against you to violate your privacy and abuse your eyeballs (sorry for the semantics, I know).