The first instance came when Debbie Reese asked how teachers handled some of the references in the Little House series. The question is a good one, one we need to consider. Using language that refers to Native people such as "redskins" and "savages" can be more than just problematic. And the books have some other incidents that should raise some concern. Read this piece done by Debbie Reese and Ebony Elizabeth Thomas for my column on censorship from The ALAN Review: http://www.alan-ya.org/wp-content/uploads/2014/11/J68-72-ALAN-Sum15.pdf. One of the responses to Reese's question came from a teacher who says she simply omits these events and references when she reads the book aloud. Guys, this is, basically, censorship. So are aps such as Clean Reads which remove the objectionable words from books.
And there is one more example of late. Here is the link to an article about a book fair rep warning about one of the books in the book fair: http://www.mlive.com/news/grand-rapids/index.ssf/2015/11/elementary_parents_notified_of.html#incart_sms_app. Parents were then informed about the "troublesome" content. Really? This is gatekeeping. We are going to "prevent" a challenge by making sure no one gets the book. I wonder in how many places this is already occurring: a well-intentioned person decides NOT to order a book or add a book to a collection because of its potential for a challenge?
So, when you see data that might suggest challenges are on the decrease, remember incidents like these. How many times does something undergo gatekeeping or censorship of another kind? I suspect the numbers might be staggering.