... any more than a cure for a disease works if no one applies it. At The New Republic, Julia Ioffe draws attention to the way in which the largely government-controlled Russian media have portrayed the recent airline crash in the Ukraine:

Did you know Malaysia Airlines Flight 17 was full of corpses when it took off from Amsterdam? Did you know that, for some darkly inexplicable reason, on July 17, MH17 moved off the standard flight path that it had taken every time before, and moved north, toward rebel-held areas outside Donetsk? Or that the dispatchers summoned the plane lower just before the crash? Or that the plane had been recently reinsured? Or that the Ukrainian army has air defense systems in the area? Or that it was the result of the Ukrainian military mistaking MH17 for Putin’s presidential plane, which looks strangely similar?

Did you know that the crash of MH17 was all part of an American conspiracy to provoke a big war with Russia?

Well, it’s all true—at least if you live in Russia, because this is the Malaysia Airlines crash story that you’d be seeing.

She goes on to point out that the absence of dissenting views (and relevant context)—oddly enough—undermine rather than strengthening government authority. That is because the media echo chamber that magnifies rumours and anger becomes a power in its own right:

After Putin’s ascent, media became the flexible element that could be readjusted for any twist or turn of the political rudder. “Today, it’s the opposite,” says Gleb Pavlovsky, a political consultant who helped Putin win his first election and was a Kremlin advisor for years afterwards. “It’s almost impossible to turn the rudder of the picture that’s formed on television because it would mean losing the audience they formed in this year” of sword-brandishing and imperialistic conquest.

Of course, our own media can be echo chambers too. But in a free society, the causes are more subtle. Here are three to consider:
1. Perhaps we choose to hear only what suits us (as one writer put it, the Daily Me). We should all make a point of spending at least some time with media others rely on, to see how the world looks to them. At times it will be enlightening, at times scary, always helpful.
2. We may be limited by type of media chosen. People who have never read a serious book may have no idea how an extended argument works, and think that if an idea cannot be condensed to 140 characters, it won’t fly. That is just not true.
3. Some biases are so pervasive that they aren’t even noticed. Not necessarily bad or unreasonable biases, to be sure. In fact, some of the most pervasive thoughtstoppers are not even noticed because they sound benign.
For example, in many cities, multimedia news coverage around homeless people takes for granted that we want to help the homeless. Quite right, but the implication may be that we must then approve and extend current efforts to help the homeless. What if it turns out that a city is spending $40,000 per homeless person per year and they are all still homeless? If the whole situation needs a serious rethink but conventional media insist on the same old heartwarmers (that do no good), we are no more likely to hear alternative views than the average Russian is likely to hear how unlikely it is that the United States wishes to go to war over the Ukraine. The only remedy is personal critical thinking.  
Here's a bipartisan discussion on media echo chambers:

Denyse O’Leary is a Canadian journalist, author, and blogger.