As anybody who has ever wistfully imagined Keith Olbermann and Bill O'Reilly fighting to the death over a pit of lava knows, most media outlets are biased. Usually it's not part of anybody's grand scheme to brainwash you, but rather just the result of newsrooms being staffed by fallible, opinionated humans.
The problem is they're generally not allowed to come right out and say they think the subject of their news story is a flaming douchebag, so they have to rely on subtle and sometimes downright dishonest methods to gently sway you one way or the other.
When you browse through the news today, keep an eye out for...
When someone uses language that implies a definite fact without stating it outright, they're using weasel words. The most common are when you attribute opinions to unnamed strangers. Ads include statements like, "Combined with diet and exercise, many experts agree that this pill could drastically increase the size of your penis and raise your credit card score." The "many experts agree" are the weasel words there.
How Can This Be Used For Evil?
If you're writing a news story, and want to insert your own opinion, you simply attribute the opinion to some unnamed person or group. Such as "many people":
The writers do not explain who is saying, asking or arguing. Their friends? God? The homeless man outside ranting about the government stealing his thoughts? Who are these people and how numerous are they? What are their qualifications?
We don't know, and in their own mind the reporter can always rationalize it with, "Well, surely there's somebody on planet Earth making that point. Why waste time actually finding them?"
Weasel words can also be used in another way, similar to the way a Straw Man is used in a debate: to introduce an anonymous but supposed common opposing argument which the writer can then rail against, as we have here:
Dude, that is not the reason we're against letting robots operate on us. It's because they'll rewire our brains and turn us into slaves, as we have plainly stated many times.