Many of us are aware that our Google searches are tailored to us to a certain extent; what I see when I google "libraries" probably isn't exactly what you'd see. What we may not have thought about is the extent to which our web experiences are being personalized for us, and what implications that can have on how we understand and interact with the world.
One feature of our online library resources, which we probably don't talk about as much as we should, is that they don't discriminate. If you and I type in exactly the same thing into exactly the same place, JSTOR should show both of us the same data, without trying to guess which articles one of us would "like." It's a more objective, and hopefully more comprehensive, presentation of options.
A good TED talk about the "filter bubble" and how it may be shrinking our world in a not-so-positive way: