It is enough to just follow two steps. (1) carefully review your google/facebook/... privacy settings (2) make a habit of logging out after you are done, or u

It is enough to just follow two steps. (1) carefully review your google/facebook/... privacy settings (2) make a habit of logging out after you are done, or use NoScript or an equivalent. If you belong to the 0.00000001% who is really paranoid, then stop using these sites, or better browse the web like Richard Stallman does.