Why this? Why that?

This article was taken from an online archive of "The Argus," one of the papers serving the Inside Bay Area [of California] updated 09/30/2006. The article was another "I make my children read banned books and I'm proud of it!" generic type of article, but it contained some information that I found interesting:

Books are challenged for many reasons. Of the 6,364 challenges reported to or recorded by the Office for Intellectual Freedom between 1990 and 2000:

-1,607 were challenges to "sexually explicit" material.
-1,427 to material considered to use "offensive language."
-1,256 to material considered "unsuited to age group."
-842 to material with an "occult theme or promoting the occult or Satanism."
-737 to material considered "violent."

Now take a look at this cartoon which I think is pretty accurate: (PIC)

Why do we see such an inversion? Why are books constantly called out on obscene language, sexual or mature situations, and references to the occult while popular television carries them all? TV is littered with mild obscenities across such shows as the sharply occult "Buffy The Vampire Slayer" and "Charmed" (not to mention the new Cartoon Network episodes of "Witch" and the newest incarnation of the Power Rangers titled "Mystic Force") and the heavily sexually charged "Desperate Housewives" "Nip/Tuck" "The OC" and practically all of MTV's programming. And yet "Of Mice and Men," "Harry Potter," and "I Know Why the Caged Bird Sings" are being publicly burned?

Something is wrong here.