In September, Melania Trump donated packages of Dr. Seuss titles to schools across the United States.

One of the schools refused the First Lady’s gift. Seuss’s illustrations were “steeped in racist propaganda, caricatures, and harmful stereotypes,” said the school in a letter to Trump.

This isn’t the first time that Seuss’s books have caused controversy. But the cartoonist and children’s author is far from alone: some of the world’s best-known books have been removed from schools or the shelves of public libraries.

Back in 1982, so many books were being challenged in the US that a number of organizations came together to start Banned Books Week, both to highlight the fact that literature was being banned, and to celebrate the freedom to read.

The American public – for instance, parents, library users and religious groups – can object to books that they think are unsuitable, particularly for young people, and ask for them to be removed or restricted.

For Banned Books Week, the American Library Association (ALA) puts together a list of the most challenged books each year across the country.

Last year’s most challenged book was This One Summer written by Mariko Tamaki and illustrated by Jillian Tamaki. The reasons were that it contained LGBT characters, drug use and profanity, and was considered sexually explicit with mature themes.

Likewise, almost all the books on the list were challenged over either LGBT themes or sexually explicit content, or both.

Image: ALA

A recent high-profile example was Jay Asher’s 13 Reasons Why, which was made into a popular Netflix series. A Colorado school district official ordered librarians to temporarily remove it from shelves after some critics claimed that it romanticized suicide.

Banned bestsellers

In some countries, bestsellers, from Harry Potter to The Da Vinci Code, have been challenged or banned.

J.K. Rowling’s famous tales about a boy wizard called Harry Potter has fallen foul of some readers’ tastes and made the fantasy series one of the most challenged on record.

A book written for an even younger audience, which narrates the true story two gay male penguins in New York's Central Park Zoo, is one of the most challenged books of the last 10 years. And Tango Makes Three by Justin Richardson has been restricted around the world. In Singapore, the book was removed from state libraries and destroyed.

In China, Winnie the Pooh is censored. References to the little yellow bear are now blocked on social media after bloggers compared him to China’s premier.

Dan Brown’s runaway bestseller The Da Vinci Code was banned in Lebanon because it was regarded as offensive to Christians.

An even more famous case is the banning of Salman Rushdie’s 1988 novel The Satanic Verses in many countries including India, Bangladesh, Egypt, Iran, Pakistan and South Africa. Iranian leader Ayatollah Khomeini issued a fatwa on charges of blasphemy and called for Rushdie’s execution. After the book’s publication, Rushdie lived in hiding for years, moving from residence to residence and with the constant presence of bodyguards.

Censorship isn’t new

Of course, opposition to books is nothing new.

The burning of books, for instance, has long been used to send a powerful political message. Four months into Hitler's regime, over 25,000 books were burnt in Munich because they were considered “unGerman”. It was such a seismic event that it is still marked in Germany today, with many of the burnt works read out in public.

Sometimes argument over censorship has ended up in court. Lady Chatterley’s Lover by D.H. Lawrence was banned in the UK until 1960 when the publishers won the right to publish the novel after a famous court case. On the first day of publication, 200,000 copies were sold.

Even books that have been sitting on bookshelves for years can come under scrutiny. At Royal Holloway, University of London, Fanny Hill, one of the oldest erotic novels in the English language (which had been taught at the university for a long time) was dropped after a consultation with students because of its pornographic content.

According to Laura Juraska, Associate College Librarian for Research Services at Bates College in Maine, books are banned for different reasons, depending on where you live.

“In the United States, it’s much more about sex and religion, and in other countries it has more to do with politics,” Juraska said. “It’s an interesting difference of what tends to get banned where. It tells you something about the culture that we live in.”

But for every book that is challenged, there are advocates fighting to get others reinstated, says the ALA.

“While books have been and continue to be banned, part of the Banned Books Week celebration is the fact that, in a majority of cases, the books have remained available. This happens only thanks to the efforts of librarians, teachers, students, and community members who stand up and speak out for the freedom to read.”