Earlier quoted context omitted.
Depends, would you walk around recording everyone with your phone out right onto their faces without their consent?
Public photography is not a crime. * a negative is: the opportunities to enjoy oneself have sadly diminished...do one 'strange' thing in public, and you're on the web.
The best way to do this would be how Google solved this with street view. Capture your public photos, blur out people's faces - better yet, respect their privacy if someone requests to not film them. Eg. Google Street view will blur out complete homes if you decide to opt out.