The Catcher in the Rye is a 1951 novel by J. D. Salinger which is famous for its themes of sexuality, angst, rebellion, alienation, and teenage confusion. This book is a driving plot point in the episode "The Tale of Scrotie McBoogerballs".
When South Park Elementary un-bans The Catcher in the Rye, Mr. Garrison's class, and particularly the boys are extremely excited to a read book that was considered so controversial and vulgar, that it was banned. However, after reading the book, they are annoyed to find it hardly vulgar by their modern standards. Upon research, the boys discover that the book supposedly caused a man to murder the famous musician and member of The Beatles, John Lennon. Unable to believe that the book could do that, the boys proceed to write their own vulgar book entitled The Tale of Scrotie McBoogerballs.