Pulitzer Prize winning photographer Narciso Contreras has been banned by the Associated Press after it came to light that he made a slight change to a photo. The AP contends that all submitted images must retain truthfulness and accuracy to the events that occurred. In this instance Contreras removed an unsightly video camera from the lower left corner of the image. While this may seem harmless apparently it doesn't fall within the guidelines of AP's standards.
Here's a quote from AP Vice President and Director of Photography from the
original article: “AP’s reputation is paramount and we react decisively and vigorously when it is tarnished by actions in violation of our ethics code. Deliberately removing elements from our photographs is completely unacceptable and we have severed all relations with the freelance photographer in question. He will not work for the AP again in any capacity.”