Interesting article on the NY Times web site:
The part I found especially interesting was about the user who posted Henri Cartier-Bresson on Flickr and got hammered. Not because it was a blatant rip off but because it didn't follow the style that is commonly seen on Flickr
“When everything is blurred you cannot convey the motion of the bicyclist,” one commenter carped. “Why is the staircase so ‘soft’? Camera shake?” wrote another. “Gray, blurry, small, odd crop,” someone concluded. That seemed to be the final word.