Speak by Laurie Halse Anderson (Farrar, Strauss & Giroux, 1999).
Speak has a been challenged most often because of what is considered to be explicit sexual content. In 2010 an assistant professor of management (?) cautioned parents in a Missouri school district that it contained "soft-pornography" and "glorifies drinking, cursing, and premarital sex," as well as teaching principles contrary to the Bible. Another reason, cited in 2021, was that the book is "biased against male students".
The Perks of Being a Wallflower by Stephen Chbosky (Turtleback Books, originally published 1999).
Since it was first published in 1999, The Perks of Being a Wallflower has been banned and challenged by several school and libraries for “profanity and descriptions of drug abuse, sexually explicit conduct and torture”; "references to masturbation, homosexuality, and bestiality"; "drugs, alcohol, sex, homosexuality, and abuse"; and last but not least, for its “offensive content”.
The Hunger Games by Suzanne Collins (Scholastic Press, originally published 2008).
In 2016, The Hunger Games took the number five spot on the American Library Association most challenged books list.
The reasons: “due to insensitivity, offensive language, violence, anti-family, anti-ethic and occult/satanic.” The novel was also banned for reasons of inserted religious perspective. However, throughout the trilogy, a religious stance is never once mentioned by Katniss or any other character.
Looking for Alaska by John Green (Dutton Books, originally published 2005).
Looking for Alaska has been challenged for multiple strange reasons including "sexual content", "inappropriate language" and because it's "too racy to read". One school challenged it because "there’s description of pornography, there’s smoking, and the book ends with a kind of question about a possible suicide".
The Curious Incident of the Dog in the Night-time by Mark Haddon (Doubleday, originally published 2003).
It has been removed from a summer reading list for "foul language". It has also been removed from reading lists because it could “pollute young minds"; for "athesim"; "the profane use of God’s name,” and a “negative portrayal of a character with autism or a similar disorder".