Captain Underpants has a new mission: to fight for banned books!

Last year, the Captain Underpants series by Dav Pilkey was on the Top 10 list of books that some grown-ups wanted to keep out of school and public libraries. That's why Captain Underpants is appearing on American Library Association posters and bracelets for Banned Books Week, which is this week.

Some adults think the Captain Underpants series is a bad influence on kids. In the books, two kids hypnotize their school principal into believing he is a comic book character. He then battles nasty cafeteria ladies from outer space and talking toilets. The adults in the stories are usually mean or stupid, or both, and there is a lot of discussion about things such as wedgies and nostril nuggets and upchucking.

Some grown-ups don't like that language, and they think the books encourage disrespect for adults. Others think the books are funny and creative. Some parents are just happy their kids are reading.

"Sometimes I have parents who kind of go, 'Euwww, Captain Underpants.' They're not thrilled . . . but they know their kids love them and their kids read them," said Jane Drabkin, a children's librarian at Chinn Park Regional Library in Prince William County.

Captain Underpants may not be great literature, but the librarians think that each family should decide which books are appropriate for them. If books such as Captain Underpants get banned, then no kids can check them out of the library -- even if their parents say it's okay.

So what do kids think? Matthew Korty, 8, of Potomac finds the idea of talking toilets "100 percent funniness."

And kids don't worry that the books' fans will imitate the behavior in the series. "It's like a make-believe story, so I really don't think that people should think that kids would do that," said Maddie Beller, 8, of Potomac.

Librarian Drabkin says that people who want to ban the books "just are not giving the kids credit for understanding that it's just for fun."

Several readers pointed out that kids couldn't copy the cartoonish action in the books even if they wanted to. After all, said 8-year-old Brandon Pelar of Springfield, "There's no such thing as a hypnotizing ring!"

-- Elizabeth Chang

Captain Underpants and other popular books have been removed from some school and public libraries.