An Iowa school district used artificial intelligence to help determine which books it would remove from libraries, the Gazette of Cedar Rapids, Iowa, reports.

The school board in Mason City in north central Iowa pulled 19 books from library shelves in its district, including frequently challenged titles from authors including Jodi Picoult (Nineteen Minutes), John Green (Looking for Alaska), and Sherman Alexie (The Absolutely True Diary of a Part-Time Indian).

The removals were a result of a new law, Senate File 496, that recently went into effect. The legislation mandates that books in school libraries must not have descriptions of sex acts.

The Mason City district used AI to detect books that depicted sexual activities. As a result, several classic books, including Margaret Atwood’s The Handmaid’s Tale, Toni Morrison’s Beloved, Theodore Dreiser’s An American Tragedy, and Maya Angelou’s I Know Why the Caged Bird Sings, were removed.

The removal is the latest in a long string of book challenges and bans that have occurred across the nation in the past few years. Picoult has been a frequent target of those challenges—earlier this month, three of her novels, including Nineteen Minutes, were banned in the school libraries in Urbandale, Iowa. She reacted to the news on Facebook, writing, “God, I’m sick of having my books banned. This time: My Sister’s Keeper, Mercy, and 19 Minutes in a suburb of Des Moines, Iowa.”

Michael Schaub, a journalist and regular contributor to NPR, lives near Austin, Texas.