This article, dated a few weeks ago, on a Chicago news radio station’s website makes it sound as though libraries are more dangerous than they are.
I suspect that many of the “thousands of files” depicting the crimes were either a question of interpretation (“I know pornography when I see it”) or relatively minor issues that, perhaps like my former place of employment, the staff wouldn’t initiate calling police unless we actually witnessed it ourselves.
If you are not familiar with it, though, check out Illinois’ Library Records Confidentiality Act for yourself. I think it benefits more than harms, and that in a criminal investigation, obtaining a subpoena for things such as telephone and library records would be part of an established process. Why should it have taken 2 days to obtain one in this case?
By the way, the act does not cover a library hiding criminal activity, as the article suggests, just circulation and usage records.
