We should be worried about online silos. They make us stupid and hostile toward each other.
Internet silos are news, information, opinion, and discussion communities that are dominated by a single point of view. Examples are the Huffington Post on the left and National Review Online on the right, but these are only a couple of examples, and not the worst, either. In technology, Slashdot is a different kind of silo of geek attitudes.
Information silos in general are nothing new and not limited to the Internet; talk radio works this way, churches and academia are often silos, and businesses and organizations study how to avoid a silo culture. But Internet communities are particularly subject to a silo mentality because they are virtually instant, meaning have no history of competing, diverse traditions, and are also self-selecting and thus self-reinforcing. The differences between online communities tend to be quite stark. That's why there are so many silos online.
It shouldn't be surprising that silos are fun and compelling for a lot of us. They make us feel like we belong. They reinforce our core assumptions, and give us easily-digestible talking points, obviating the necessity of difficult individual thought. They appeal to our epistemic vanity and laziness.
That's one of the problems. Silos make us overconfident and uncritical. Silos worry me because critical knowledge—the only kind there is, about anything difficult—requires a robust marketplace of ideas. Silos give too much credence to objectively unsupportable views that stroke the egos of their members; in a broader marketplace, such ideas would be subjected to much-needed scrutiny. Silos are epistemically suspect. They make us stupider. They might be full of (biased) information, but they make us less critical-thinking and hence lower the quality of our belief systems.
It can be "social suicide" to criticize a silo from within the silo, while external criticism tends to bounce off, ignored. So silos tend to become hostile to dissent, empowering fanatics and power-seekers at the expense of the more moderate and the truth-seekers. Silos also alienate us from each other, even from friends and family members who don't share our assumptions, because it is too easy and fun to demonize the opposition from within a silo. The rise of the Internet seems to correlate with the rise, in the late 1990s and 2000s, of a particularly bitter partisan hostility that has, if anything, gotten worse and made it increasingly unpopular and difficult to reach meaningful political compromises. This threatens the health of the Republic, considering that compromise has been the lifeblood of politics since the founding.
My solution? For one thing, you can do your part by regularly visiting the opposition and showing them in conversation how reasonable you can be. There's little more upsetting to a silo than infiltration by an intelligent, persistent individual.