One of the incredible feats of media journalists is denying that there is media bias by equating it with conspiracy theories. When people share the same bias, they don't need a conspiracy. The harm comes from the fact that most of the public gets to see only that part of reality which has been filtered through the same preconceptions shared by 90 percent of those in the media.
For example, it has been endlessly repeated in the media that the United States has a much higher murder rate than some countries with more restrictive gun control laws. But the media pass over in utter silence the fact that there are other countries, such as Russia, which have more restrictive gun control laws than ours but have far higher murder rates than the United States.
The media have obviously made up their minds that restrictive gun control laws are desirable, which they have every right to do. It is when they try to make up other people's minds by filtering out information to the public that their opinion become a bias in doing their job.
When vicious, sadistic murders are committed by whites against blacks, or straights against gays, that news is trumpeted throughout the media. But when similar atrocities are committed by blacks against whites, or gays against straights (including children), there is again utter silence in most of the media.
Instead of learning that some terrible and vile things have been done by human beings of every race, color, creed, national origin, and sexual orientation -- in countries around the world -- the message of the media is that some groups are victimized by American society. That is media bias, made more insidious by the fact that it is not expressed openly as editorial opinion, but by corrupting the reporting of news.
Anyone listening to Rush Limbaugh knows that what he is saying is his own opinion. But people who listen to the news on ABC, CBS, or NBC may imagine that they are getting the facts, not just those facts which fit the ideology of the media, with the media's spin.