My contribution to the conversation was exactly this idea: that the subtler problem with web-based news was how easy it becomes for like-minded kooks to come together and confirm each others' realities. In some cases, this is a good thing -- like how D&D players or startup founders can find each other and form communities. But in the case of semi-delusional, 911-was-an-inside-job, birther, we-didn't-go-to-the-moon types, or even Rush Limbaugh's misinformed dittoheads, what we have is a fragmentation of reality, in which each subculture occupies a different narrative about what is happening in the world. It's like a Philip K. Dick novel.
After I disgorged my profound insight, the 75-year-old told me it has always been that way. :)
But it does seem plausible that the web is accelerating and amplifying the tendency.