The Internet makes it easy for people to create separate communities and niches, and in a free society, much can be said on behalf of both. They can make life a lot more fun; they can reduce loneliness and spur creativity. They can even promote democratic self-government, because enclaves are indispensable for incubating new ideas and perspectives that can strengthen public debate. But it is important to understand that countless editions of the Daily Me can also produce serious problems of mutual suspicion, unjustified rage, and social fragmentation — and that these problems will result from the reliable logic of social interactions.

We've had this conversation here before.