How Can These Books be Banned?

I know this is a little off topic for this blog, but when I "re-invented" it, my intention was to broaden its scope. I came across a link to libraryland on NPR this morning and followed the link to the 2011 Banned Books List. I've read a lot of these books. I seriously doubt they're banned in the U.S (unless we're talking about public school libraries and such). or in many western nations. Too bad NPR or Libraryland failed to run even a small explanation about where these books are banned and under what conditions people are forbidden to read them.