What does this have to do with "out in public"? I have by law, custom, and common sense an expectation of not being 3D-scanned in a gas station bathroom, even if I pick up the phone that the previous visitor had dropped on the floor.
And if the previous visitor was on a Skype call with someone while in that bathroom, dropped the phone on the floor, and walked out, and you walked in and picked up the phone, you would have the same issue.
Many privacy-conscious settings that I've been in prohibit phones entirely.
In most countries you have no right not to be photographed (by anyone) when in public (by definition being in public is not being in private). I fully support this with the exception of the homeless (and I think it does somewhat support the right to cover your face in public if you wish).
