I heard it a couple times on v7n. A couple of our in house atheists referred to it as child abuse or something along those lines. Then I was over on another community today where their was another pompous windbag of an atheist with his spewing of hatred at all religions (even those cute ones like Hindu and Buddhism), and I mentioned that it's not cool to stir up hatred. The response was something along the lines of, until parents are prevented form teaching religion to children, religious people need to be attacked.
Anyhow, the source is Dawkins.
"Religion equals 'child abuse'"
I knew a public school teacher who opposes private schools because they "cheat" public schools out of the chance to teach children that religions are false.
Yeah, kids are the battlefield. Smart tactic, too. Teach 'em to be Liberals from the time they are kids, and you don't have to do it later when they are able to employ critical thought.