Major, formerly reputable, news operations like NBC have given up completely on journalistic integrity in favor of controlling the message. Two recent incidents with NBC show my point.
First there is the matter of the edited 911 call made by George Zimmerman in the Travon Martin case. By the time NBC picked up the story it was already being cast as an instance of racism. The 911 call did not support that so a senior NBC editor doctored it. In the original call, Zimmerman described Martin's behavior as suspicious but only added martin's race when prompted. NBC (and CNN) removed the 911 operator's question leaving the impression that Zimmerman included Martin's race as something that made him suspicious.
Later analysis of all of Zimmerman's 911 calls showed that he never identified someone's race until asked. Further, it was a mix-ed race neighborhood so simply seeing a black youth would not have been suspicious. It was his behavior, standing in rain in a yard instead of on a sidewalk, that Zimmerman was reporting. By editing the tape, NBC made it seem that Zimmerman was reporting someone for walking while black.
More recently, NBC reported on Rudolph Giuliani had endorsed Mitt Romney. Except the footage they played was from earlier when Giuliani was supporting Newt Gingrich and complained about Romney flipping on issues. Showing an anti-Romney soundbite is likely to leave more of an impression than reading a pro-Romney endorsement. So, by choosing the right footage, they turned a pro-Romney story into an anti-Romney one. This is a rather stunning case of bias.