Yes, in the US, the current state of the law is that anything done in public is fair game for anyone - there is no expectation of privacy when in public.

However, this point of law was determined back in the late 60's or early 70's, back when the concept of an indexed database of millions of permanent records of essentially everybody in public was barely even the stuff of science fiction, much less everyday fact. I think we are long overdue for a revaluation of the legal situation given the drastic change in circumstances of the last 40 years.