Judge in Iowa blocks Republican-backed law banning books depicting sex acts in school libraries, calling it a puritanical restriction on free speech. Penguin Random House, John Green, Jodi Picoult challenge law on free-speech grounds. Injunction also blocks limits on sexual orientation and gender identity education. Republicans dismiss concerns, emphasizing protection of children. Governor Reynolds vows to protect children's innocence. Law's broad scope causes removal of non-sexual books. Lawsuit filed regarding entire measure. Iowa's shift to right reflected in recent legislation.