In my experience, the main issue I've encountered with photographing people is "What are you going to do with it?" People seem to live in this oddball fantasy world where they think that photos will be used against them somehow, like gee I might be on the internet and someone might see me doing something and I don't like that. People generally seem to think they matter more than they really do, and a healthy dose of paranoia is commonplace. Sure, I can see a cop being worried, but, hey, don't do something stupid and you don't have to worry who is photographing or filming you. The general public? Unless you are a fugative or are somewhere you shouldn't be, like cheating or commiting some crime, or you truly don't want to be identified, like I figure some homeless are from the attitudes I've gotten from some...get over yourself, no one really cares who you are or what you think you don't want anyone to know about. It's the everyman on the street that is afraid of everything...I've met true recluses out in the desert, people who actively avoid society, and not once have I ever been refused a photograph.