Comment 6 by Starcrash :

Perhaps we could get kids to spread the word of Islam or anti-theism by abusing the same loophole (in order to demonstrate to the Christians why it's wrong) but two wrongs don't make a right, and we don't want to indoctrinate children.

Two wrongs can sometimes make a right, if indirectly. In the schools where this is going on, I see nothing wrong with doing the same thing they're doing. When they go insane, let it go to court. All along, the point would be made as to what our motivations were: Not indoctrination, not even spreading our own message; just getting their religion out of places it doesn't belong.

Or, we can sit in the shadows, looking dejected and feeling sorry for ourselves like cowardly losers, not knowing what to do. Haven't we done that for long enough?