Every year, kids go to school or the library and bring back books that make some parents raise their eyebrows. Such language! Boy wizards! Sexual situations! Underpants!

There are formal complaints lodged - more than you might expect in 2014. The American Library Association keeps an annual tally, and rather than hide those books away, it brings the challenges out in the open.

This is Banned Books Week, observed at libraries and bookstores nationwide. It celebrates books that long ago were the focus of legal battles over censorship, like Lady Chatterley's Lover, by D.H. Lawrence, Allen Ginsberg's Howl, and James Joyce's Ulysses, as well as the most-banned and challenged book of the last year.

This year, Dav Pilkey makes the top 10 again, topping the list at No. 1. Never mind that his Captain Underpants series about two fourth graders and their silly superhero has sold tens of millions of copies - it still makes parents and guardians crazy. Their official complaints include "offensive language," "unsuited for age group," and "violence."

Other authors whose books are among those most frequently banned or challenged include bestselling YA author John Green and Nobel Prize-winner Toni Morrison.

The list:

10: Bone (series) by Jeff Smith. Reasons: political viewpoint, racism, violence.

9: Bless Me, Ultima by Rudolfo Anaya. Reasons: occult/Satanism, offensive language, religious viewpoint, sexually explicit.

8: The Perks of Being a Wallflower, by Stephen Chbosky. Reasons: drugs/alcohol/smoking, homosexuality, sexually explicit, unsuited to age group.

7: Looking for Alaska, by John Green. Reasons: drugs/alcohol/smoking, sexually explicit, unsuited to age group.

6: A Bad Boy Can Be Good for a Girl, by Tanya Lee Stone. Reasons: drugs/alcohol/smoking, nudity, offensive language, sexually explicit.

5: The Hunger Games, by Suzanne Collins. Reasons: religious viewpoint, unsuited to age group.

4: Fifty Shades of Grey, by E.L. James. Reasons: nudity, offensive language, religious viewpoint, sexually explicit, unsuited to age group.

3: The Absolutely True Story of a Part-Time Indian, by Sherman Alexie. Reasons: drugs/alcohol/smoking, offensive language, racism, sexually explicit, unsuited for age group.

2: The Bluest Eye, by Toni Morrison. Reasons: offensive language, sexually explicit, unsuited to age group, violence.

1: Captain Underpants series by Dav Pilkey. Reasons: offensive language, unsuited for age group, violence.