I think it would be terribly simplistic to try and psycho-analyze someone based on what pics they post on fb.

People are much too complex to try and boil it down to a formula.

And, besides, generalizations are dangerous by their very nature.

Moods change, interests change---and people's needs for privacy and security also change fairly regularly.

There are all different levels of openness and familiarity there. So try not to over-simplify something that is actually terribly complex, and based solely on appearances (always a tricky thing!).