FFS George, our problem with the census and it's ilk isn't just those law abiding citizens. It includes the less savoury types who are already flaunting several laws to get it in the first place. There's also the small matter of the more than 6 billion people out there who are not subject to our laws.
Rather spend your effort instilling a culture of individual's privacy, to only collect the minimum data required to perform the specific functions and to viciously guard against mission creep by unaccountable bodies. Cut bonuses from departments that leak private data and use it to compensate the inevitable victims of those leaks