If an atheist walks into a school and
Not according to the Bible. As long as he takes at least some of the kids home to use as sex slaves then he's well within the boundaries of the scripture and hence has done nothing wrong. Supporting evidence:-
Now kill all the boys and all the women who have slept with a man. Only the young girls who are virgins may live; you may keep them for yourselves.
(Numbers 31:7-18 NLT)