How do I do that if I don't have an account? Also, if I do have an account, will that delete all of the crap doubleclick and friends shared with each other while I was logged out?
Do you actually believe it will delete anything? You're wrong. NSA would still get the data, and so would Google for marketing purposes. It's just to calm privacy-aware, but not techsavvy users.
The NSA will collect it on the wire anyway. They have drilled in and tapped underground fibre optic cables on private networks behind HTTPS load balancers before, and simply captured what they want.