There is a very nice book written with different essays on photography as it is seen or has been received by "other" cultures. it is called "photography's other histories" and is very interesting:
is a link to a description of the book.

I think that this is closely connected to weighing the "damage" you might inflict taking photos of others (even in your own culture) against the "good" you intend your photos
to do..

every time you take a photo of a photo of someone this is a question you need to have straightened out in my view, and photographing someone from another culture (or places etc. belonging to another culture) only makes this a harder question to answer...