It's good that you bring up sex trafficking; I didn't even get that far in my post. You're right that these people will spend a lot of time grooming children. And if for some reason, one child or that child's parents get wise and cut off communication, it probably won't make much of a difference to the predator who is talking to many potential victims at once. A scary thought.

There's a movie on Netflix called The Chosen Ones (2015) that depicts a girl who is entrapped in a prostitution ring by her boyfriend and his family. If you don't mind foreign films (it's in Spanish), I'd recommend it. It's an interesting take on the subject.