When I say biased, I mean that they do more than report news based on the information they have; they want to tell a story with an "angle", so they speculate, or interview "experts" to speculate on the meaning of, or reason for a news event. If they were unbiased, they would report what they knew as facts, and not speculate.
Well yes, but, as others have also stated here, this already happens for a long time. If they make a report about some exotic region which I happened to have travelled, they create a certain specific story about it (which may not have much to do with what you might find there on average). If they make a report about some special people, lets say Wiccans Beltaine festival, they are looking for sex orgy - when they did make report about hackers, they didn't care about ethics or security, but wanted to have some spectacular break-in.
So there are three lines: first, it has to be something that catches the readers/watchers, so it has to be spectacular or exaggerated. Second, it has to be in-line with the political bias of the respective media (one can find these out).
And third, there is a couple of fairytales our whole culture has commonly agreed to believe in. For instance, before christmas, when all the charity organizations collect money, they usually advertize their business with a picture of an african baby. So what does that mean: that african baby is obviousely not considered as a human individual with a dignity, instead it is merely an icon to transfer a message, it is a simple glyph with the meaning "poverty". I tend to call that abuse. And travelled part of Africa, and what I have seen is a lot more, and a lot more differentiated than the storyline usually brought up in the media - the latter most often only circulating around how helpless the people there are and how dependent on our help (=money).
I think this is something that is intended to be commonly believed by the news consumers. And tentatively I might go as far as assuming this might be a remainder of colonialism viewpoints: now the Africans are no longer considered as countries that can simply be annexed and exploited because they would be too stupid to manage their own, but still are considered as dependent on our gratitude because too stupid to manage their own.
So this is an example for imagery, storylines that go thru almost all the media, and still may not be fully true or even ethically questionable.