It's a ridiculous conspiracy theory. Newtown is as ordinary a town as you will find in the US. What do you think the odds are of having a public school full of ordinary people that have nothing in common with one another than that they work in a school all involved in the conspiracy and not even one person snitches?
I agree it was planned- by Adam Lanza. Evidence shows this was not a spur-of-the-moment act by a crazy person, but a carefully planned and premeditated act by an evil person, who also happened to be crazy.