If you Google some sites about the link between vaccines and autism, you can very quickly find that Google is repeating back to you your view about whether that link exists and not what scientists know, which is that there isn't a link between vaccines and autism. It's a feedback loop that's invisible.

It feels great to have your own views reflected back to you, and you feel so right, but actually it's very dangerous. Because to make good decisions, you need to have a clear view of what all the options are.

By constantly moving the flashlight of your attention to the perimeter of your understanding, you enlarge your sense of the world.

In a personalized world, important but complex or unpleasant issues are less likely to come to our attention at all.

Whether it's Facebook or Google or the other companies, that basic principle that users should be able to see and control information about them that they themselves have revealed to the companies is not baked into how the companies work. But it's bigger than privacy. Privacy is about what you're willing to reveal about yourself.

A world constructed from the familiar is the world in which there's nothing to learn.

If you Google some sites about the link between vaccines and autism, you can very quickly find that Google is repeating back to you your view about whether that link exists and not what scientists know, which is that there isn't a link between vaccines and autism. It's a feedback loop that's invisible.