>Because they are easy targets
Wrong.
It's because they are packed full of potential energy.
"Stealing of innocence".
You are.
They are easy targets in some ways but these people have ways of getting whatever they want (used to any ways).
Children are taken in their dark arts because of a reality as old as time.
Call it "life force", "energy", "Divinity"…
Crowley called it Innocence.
It's what [they] are after.