• Profanity.  Books are often challenged for the language they contain, even though profanity is often used in literature to convey social or historical context, local dialect or simply to better depict reactions to real-life situations. Books such as Of Mice and Men by John Steinbeck and Slaughter-house-Five by Kurt Vonnegut have been challenged or banned due to objections to profanity.
  • Sex.  Books as varied as Judy Blume's Forever, Vladimir Nabokov's Lolita, and Maya Angelou's I Know Why the Caged Bird Sings, among many others, have been challenged by parents and school boards who deem certain sexual passages inappropriate for young people. Works such as It's Perfectly Normal by Robie Harris and Heather Has Two Mommies by Leslea Newman, among others, face demands for removal for their frank discussion and focus on gay/lesbian issues.
  • Violence.  Objections to violent content are often based on the idea that these works trivialize violence or desensitize readers to its effects. Books challenged on these grounds include One Fat Summer by Robert Lypsyte and Native Son by Richard Wright.
  • Religion.  Religious grounds have long been cited as reasons for censoring books. Reading translations of the Bible was once forbidden. Today, parents and ministers often object to works which discuss topics such as sex, evolution, or witchcraft or occult themes.