Watch this infuriating interview from CNN regarding Wikileaks. And while doing so keep in mind that CNN ostensibly is tasked with doing journalism. That is, if they are pursuing their perceived function they should be trying to uncover corruption/immoral behavior by powerful officials that work contrary to the public interest.
The difference between what the media portray themselves as doing and what they actually do was long ago explained by Ed Herman and Noam Chomsky when they offered their Propaganda Model for the media. They say that based upon an institutional analysis of what the media is and what it's incentive structure is, we should expect it to largely be an enterprise that is in service to power, not an institution that undermines power when that is in the public interest.
Herman and Chomsky proved that their model was correct in a number of ways. One way was to take the examples that are often put forward as evidence that the media is iconoclastic and examining them in detail to show that this perception is false. People perceive that media coverage of the Vietnam War was largely negative and played to the interests of the anti-war movement. Many think that this negative coverage undermined the war itself and worked against the interests of the powerful factions that were perpetuating that war. In fact that is just the opposite of the truth. For the details you'll need to check out Manufacturing Consent.
I think the above interview is another good illustration. The host and government spokerperson's views are pretty much identical. They disparage and criticize an institution that is in fact doing what journalists ought to be doing if what they did wasn't service to power. CNN is hostile to iconoclastic journalism so naturally they oppose Wikileaks.