When in a public place a person has no expectation of privacy. Their image can be taken. This is how the upskirt guy in Boston was found not guilty. What he was doing was NOT against the law. This little loophole got closed really quick. In a private establishment the owner's rules rule. On your front doorstep you have the right to say no pics, and have a sign in your lawn that says no pics. Problem is, if the person is standing on the street then technically their is no way you can stop them. Some bigwigs are challenging this. How successful they are depends wholly on who they are and what jurisdiction they are in.
Unfortunately people assume tha,t because they are able to take a picture, they should take the picture. Further proof of the narcissistic road society is traveling down.