Between 1990 and 2000, of the 6,364 challenges reported to or recorded by the Office for Intellectual Freedom (see The 100 Most Frequently Challenged Books):

• 1,607 were challenges to “sexually explicit” material (up 161 since 1999);
• 1,427 to material considered to use “offensive language”; (up 165 since 1999)
• 1,256 to material considered “unsuited to age group”; (up 89 since 1999)
• 842 to material with an “occult theme or promoting the occult or Satanism,”; (up 69 since 1999)
• 737 to material considered to be “violent”; (up 107 since 1999)
• 515 to material with a homosexual theme or “promoting homosexuality,” (up 18 since 1999) and
• 419 to material “promoting a religious viewpoint.” (up 22 since 1999)

Other reasons for challenges included “nudity” (317 challenges, up 20 since 1999), “racism” (267 challenges, up 22 since 1999), “sex education” (224 challenges, up 7 since 1999), and “anti-family” (202 challenges, up 9 since 1999).

Please note that the number of challenges and the number of reasons for those challenges do not match, because works are often challenged on more than one ground.

Seventy-one percent of the challenges were to material in schools or school libraries.² Another twenty-four percent were to material in public libraries (down two percent since 1999). Sixty percent of the challenges were brought by parents, fifteen percent by patrons, and nine percent by administrators, both down one percent since 1999).

¹The Office for Intellectual Freedom does not claim comprehensiveness in recording challenges.

²Sometimes works are challenged in a school and school library.