If a "street photographer" shoots a picture inside a building..

[goamules]

Street photography is a broad genre. City photography, sidewalk photography, park photography, and concert photography would be narrower genres, if they rise to the level of genres.

Say, that reminds me: why do we call them genres? Why not "categories" or something simpler like "ephemeral extemporaneous detritus"?

 

[bmattock]

If a street photographer takes a candid photo of the back of someone walking away and there's no one there to admire his gear or bokeh, does he make a sound?

 

[Rayt]

If a fellow photographer asked what do I shoot and I reply "street photography" then there is an understanding what I am talking about. This is what communication is about isn't it? If a non photographer asked the same question I would probably say travel photography (if I happened to be traveling) or documentary photography which is more descriptive. The follow up question would inevitably be "what do you document" rather than "you shoot streets? What if you are indoors"?. It doesn't matter what you call it as long as you manage to convey the meaning behind the words.