To add to this:

Modern libraries are one of the few remaining places where you don't get thrown out just for loitering. They're free wifi-enabled, air-conditioned spaces. I worked at one, in an extremely affluent area, for several years. Our problem was, partially, with children, as kleinbl00 says -- though that was mitigated by the partitioning of the children's section -- but overwhelmingly with homeless people who had nowhere else to be. We couldn't throw them out until /after/ they had already disturbed the supposed inherent quiet of the library, and most did, inevitably, because the majority had mental illnesses and no family. I talked to dozens of them.

My point with all this is that a large part of kleinbl00's post above is overly general. (Silence is freely available at reading rooms? We had a reading room, even though I was under the impression that libraries really were reading rooms anyway, at my old job -- and people went in their to make calls. What can ya do.) I side with the article on this one.