Street Photographer's Right

Question:

Is model release needed from the person captured in street shots which are not used commercially?

 

There was a street shot posted by my nephew: HERE. The person captured in the photo was pretty furious with that post and requested to have it removed from his Flickr site.

 

My nephew has removed it from his photostream out of respect for her.

 

I hope to take this opportunity to seek your opinion about our right in terms of photographing human subject on the street.

Done