I don't have an issue with the mentally ill, mentally handicapped, or anyone else using libraries provided they are able to behave somewhat reasonably and are using the library (mostly) for its intended purposes. Our library doesn't oust people who are not causing the problems I listed above. The problems arise when they either get in the way of students and professors or act in a manner that is disruptive.

Apparently, we had one person coming in for awhile that we tolerated until he started muttering about Jews, "ni**ers", and "ragheads" and became confrontational with the reference desk staff (who are black, Latino, and Filipino), and may have made some remarks within earshot of several Muslim [wearing hijabs] medical students. He was neither student, faculty, nor staff, of any of our associated organizations and we finally had to bar him from the premises.

I wholeheartedly agree that better facilities are needed for people like that, but libraries aren't the answer.