[ergodic]

IMO the economical argument is the most robust. I see it like this:

There is a big margin between

1) the amount of information that you are legally obligated to provide to public and private sectors

2) the amount information that can be mined about you through facebook and other services (+smart data-crunching)

Safeguarding that information that falls between 2 and 1 is not a matter of moral standpoints or having something to hide. It has only to do with a properly informed rational decision about your personal economy and your well being.

That information that you are willfully leaking will weaken your position in any future negotiation including, financial credit, insurance and employment among others. After Cambridge Analytica it is more clear than ever that it will also weaken your ability to protect yourself against well armed psychological manipulation.

and that is all assuming that public and private institutions do not make mistakes, that legal boundaries and procedures are flawless and that you leave in a well executed democracy.