If you see above, jab2 vouches for the source - and it seems very well documented and done by reliable university professor researchers. It's not that easy to get someone who wants to face the social and logistical consequences of suing, I guess - and it may be percolating through the courts as well. Plus, since sex ed courses are usually optional, I suspect that the districts may have an out by simply saying that non-Christian kids can choose not to take the course.