This can be a very divisive issue. On the one hand is the right of a person to a modicum of privacy - "The right to be let alone." as one of our chief justices put it. On the other hand is the right to a free press, which is something more now than newpapers and television.
If a picture is found on the web disclosing the location at a given time, of a person who is supposed to be somewhere else, or whose situation is such that another could concievably use the information for harm, the photographer might be liable, in some way.
If you don't wish to have photographs taken of you while you are in public places, you could possibly wear a mask or veil, though in some jurisdictions, this is, in itself against the law.
I have seen, in my lifetime thus far, a diminution of freedom in the U.S.A. There are quite a lot of people now who seem to think that a desire for privacy is, somehow sinister. Younger people, particularly, seem to not even have the concept.
Personally, I don't post for public consumption, recognizable pictures of others unless I have explicit permission. (except for my cat)