Eli Pariser said it in The Filter Bubble. Clay A. Johnson experienced it as he described in The Information Diet, in the campaign by Howard Dean to be elected president of the US. Many people felt the effect as a big jolt when the election results from this last election came in. You can see how it goes: you read, you listen, you watch. You gather info and you work hard at it.
If you are thorough or scholarly or persistent, you may look at documents behind documents. You may look at sources and originals. By the time you have come to a conclusion, you feel that you have looked at the issue or the subject from all angles. If you find someone has a different conclusion, it is only logical to assume they aren't as thorough or scholarly or persistent, they aren't as deep as you, they haven't read as closely and carefully as you have.
The difficult truth is that you and I can watch the same news report, read the same document and come to the end with different opinions. I realize that your opinion is probably based on slanted, handpicked evidence while my opinion is based on broad reading and careful analysis. Oddly and mysteriously enough, you realize that my research and consideration has been biased and slanted and doctored without my realizing it. Pariser pointed out that if I always rely on Fox News while you always read the Christian Science Monitor, we are steadily consuming different diets of information. Clay Johnson was stunned that the candidate he had worked very hard for, a man he admired and supported, did so poorly in early state contents. Then, he realized that for months, he had been immersed in groups and a staff that felt just as he did, that he had been working in a bubble that filtered out counter feelings and reactions.
It seems to me that David Weinberger summed the current knowledge and communication situation up accurately with the title to his book, "Too Big to Know". The internet and many of the issues are literally too big for any of us to fully know. You don't have time, energy or interest in reading all the sources I find relevant and I feel the same way about what you spend time on. I have read that the legal systems in many countries are not arranged as ours is, with a prosecuting attorney and a defense attorney. But if I prepare to debate the proposition that A is better than B and you prepare a position that B is the better, we will almost certainly look at and remember and be moved by different authors and ideas. Even my intelligent and quick-thinking PhD wife tends to see things differently from the way I do. I often simply cannot get her to see straight.