Human nature is a funny thing. If you tell someone they can't do something, they want to do it more. This is especially true when it comes to banned books. People are always drawn to the library's Banned Books displays, wanting to know who banned them and why, and eager to clap their eyes on this forbidden fruit. Whether it be the Satanic Verses or Harry Potter and the Order of the Phoenix, don't hesitate to ask your friendly neighborhood librarian for access to banned books. As champions of intellectual freedom, we are happy to hook you up!

These days, book banning most frequently occurs in schools and public libraries, usually at the insistence of parents or community leaders who find certain books inappropriate for a variety of reasons. Of course, just because a book is banned doesn't mean that it ceases to exist. Publishers still publish these books and retail outlets still sell them—and, of course, most libraries still stock them on their shelves. But it wasn't always like that.

For thousands of years, the written word was only available to the 1%—primarily royalty, nobility, and scholars. It existed in the form of handwritten manuscripts and scrolls, and only the elite had access to them—or, indeed, even knew how to read.

That all changed in 1440 with the invention of the printing press. Pamphlets, books, placards, and newspapers were suddenly everywhere, and people quickly decoded these writings and formed new opinions based on the information they contained. For the first time, the masses were exposed to a wide range of viewpoints on history, science, the arts, religion, and philosophy.

Then the hammer came down.

Pope Paul IV ordered the creation of the first Index of Prohibited Books in 1559. Authors on this early banned list included Protestant Reformation leader Martin Luther and scientist/philosopher Galileo Galilei.

In 1662, England imposed a Licensing Act that limited the content and number of newspapers and newsletters that could be published and disseminated, which was spurred by the fear that unlimited access to information would be harmful to society and public morals.

In the 1800s, newly published titles such as Huckleberry Finn, Madame Bovary, and The Hunchback of Notre Dame were among the most frequently banned, along with the fairy tales of Hans Christian Andersen and the Brothers Grimm.

In 1921, the American magazine The Little Review was declared obscene for publishing James Joyce's seminal novel Ulysses in serialized installments. The objection was due to (among other things) the novel's depiction of masturbation and the human body. When Ulysses was published in book form in 1922, the New York Society for the Suppression of Vice tried to keep it out of the country, and the United States Post Office burned copies of the book that had been imported from England. Finally, in 1933, a U.S. District Judge ruled that the book was not pornographic because it did not incite lust and therefore could not be obscene.

In Nazi Germany during the 1930s, a campaign was instigated by the German Student Union that included public ceremonial book burnings of works by Jewish, pacifist, religious, socialist, and communist authors, among others.

Margaret Atwood's The Handmaid's Tale was one of the most frequently challenged books of the 1990s. Its depiction of the subjugation of women in a not-too-distant dystopian society was banned in numerous high schools on the grounds that it was "rife with brutality" and too sexually explicit.

These are but a few examples of book banning over the years—a practice that, unfortunately, still exists today. Below is a list of the most frequently banned books of the 21st century (so far), along with the reason each work was deemed "inappropriate." What better way to celebrate Banned Books Week than to choose one (or several) books from this list and then check them out at your local library?

The Most Frequently Banned Books of the 21st Century (So Far)

Source: American Library Association

Looking for Alaska by John Green
Young Adult Fiction

Reason it's banned: A sexually explicit scene that may lead students to "sexual experimentation."

Scary Stories to Tell in the Dark by Alvin Schwartz
Children's Fiction

Reason it's banned: Unsuitable for age group, violence.

Uncle Bobby's Wedding by Sarah S. Brannen
Picture Book for Young Children

Reason it's banned: Homosexuality, unsuitable for age group.

Fifty Shades of Grey by E.L. James
Adult Fiction

Reason it's banned: Sexually explicit, poorly written, concerns that teenagers will want to try it.

Beyond Magenta: Transgender Teens Speak Out by Susan Kuklin
Young Adult Nonfiction

Reason it's banned: Anti-family, offensive language, homosexuality, sex education, political viewpoint, religious viewpoint, unsuitable for age group.

I am Jazz by Jessica Herthel and Jazz Jennings
Children's Nonfiction

Reason it's banned: Language, sex education, offensive viewpoints, portrayal of a transgender child.

The Holy Bible, New International Version
Religious Text

Reason it's banned: Religious viewpoint.

The Curious Incident of the Dog in the Night-Time by Mark Haddon
Adult Fiction

Reason it's banned: Profanity and atheism.

Two Boys Kissing by David Levithan
Young Adult Fiction

Reason it's banned: Cover image, sexually explicit LGBT content.

And Tango Makes Three by Peter Parnell and Justin Richardson
Picture Book for Young Children

Reason it's banned: Homosexuality, unsuitable for age group.

The Absolutely True Diary of a Part-Time Indian by Sherman Alexie
Adult Fiction

Reason it's banned: Anti-family, cultural insensitivity, drugs/alcohol/smoking, gambling, offensive language, sex education, sexually explicit, violence, depictions of bullying.

Revolutionary Voices edited by Amy Sonnie
Young Adult Nonfiction

Reason it's banned: Homosexuality, sexually explicit.

It's Perfectly Normal by Robie Harris
Children's/Young Adult Nonfiction

Reason it's banned: Nudity, sex education, sexually explicit, unsuitable for age group.

The Kite Runner by Khaled Hosseini
Adult Fiction

Reason it's banned: Offensive language, violence.

A Stolen Life by Jaycee Dugard
Adult Nonfiction

Reason it's banned: Drugs/alcohol/smoking, offensive language, sexually explicit.

The Adventures of Captain Underpants by Dav Pilkey
Children's Fiction

Reason it's banned: Offensive language, unsuitable for age group, violence.

The Perks of Being a Wallflower by Stephen Chboksy
Young Adult Fiction

Reason it's banned: Drugs/alcohol/smoking, homosexuality, offensive language, sexually explicit, unsuitable for age group, date rape, masturbation.

A Bad Boy Can be Good for a Girl by Tanya Lee Stone
Young Adult Fiction

Reason it's banned: Drugs/alcohol/smoking, nudity, offensive language, sexually explicit.

Beloved by Toni Morrison
Adult Fiction

Reason it's banned: Sexually explicit, religious viewpoint, violence.

Bless Me, Ultima by Rudolfo Anaya
Adult Fiction

Reason it's banned: Occult/Satanism, offensive language, religious viewpoint, sexually explicit.

The Glass Castle by Jeanette Walls
Adult Nonfiction

Reason it's banned: Offensive language, sexually explicit.

The Hunger Games by Suzanne Collins
Young Adult Fiction

Reason it's banned: Religious viewpoint, unsuitable for age group, violence.

Thirteen Reasons Why by Jay Asher
Young Adult Fiction

Reason it's banned: Drugs/alcohol/smoking, sexually explicit, suicide, unsuitable for age group.