Should some books be removed from libraries?

This is a question that has circulated for as long as I can remember. Here is a link to a well thought out response to this question.
A woman strongly opposes a book which is shelved in the children's section of the library. It deals with gay marriage. The response covers all bases of the woman's concerns. I have to agree that if you do not like a subject, it does not mean it should be removed. Should we homogenize our books stores and libraries? I understand that adult information should be kept from children. I mean who wants our children exposed to x rated material? Common sense should prevail when categorizing such material. The subject matter at the center of this particular complaint covers gay marriage which, like it or not, is part of today's society. If a child is removed from such controversial realities, is it a good idea? The child will grow up totally ignorant of such things. When they become independent adults they are in for quite a shock. If the mother strongly disagrees (or agrees) with something, then discuss the topic with the child instead of hiding it. Give the child intelligent facts on the subject. This way the child is equipped with valuable information in order to deal with the world. Otherwise, the child will eventually go out in the world totally unprepared to deal with life's nuances.